Denial of Service
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
How It Works
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions. Attackers exploit asymmetry: minimal attacker effort produces disproportionate resource consumption on the target. Application-level attacks use specially crafted inputs that trigger expensive operations—a regex engine processing malicious patterns can backtrack exponentially, or XML parsers recursively expand entities until memory exhausts. Network-level attacks flood targets with connection requests or amplify traffic through reflection, but application vulnerabilities often provide the most efficient attack surface.
The attack typically begins with reconnaissance to identify resource-intensive operations or unprotected endpoints. For algorithmic complexity attacks, adversaries craft inputs hitting worst-case performance—hash collision inputs filling hash tables with collisions, deeply nested JSON triggering recursive parsing, or pathological regex patterns like (a+)+b against strings of repeated 'a' characters. Resource exhaustion attacks open thousands of connections, upload massive files to unbounded storage, or trigger memory leaks through repeated operations. Crash-based attacks target error handling gaps: null pointer dereferences, unhandled exceptions in parsers, or assertion failures that terminate processes.
Impact
- Service unavailability preventing legitimate users from accessing applications during attack duration
- Revenue loss from downtime in e-commerce, SaaS platforms, or transaction processing systems
- Cascading failures as resource exhaustion spreads to dependent services or database connections pool out
- SLA violations triggering financial penalties and damaging customer trust
- Security team distraction providing cover for data exfiltration or intrusion attempts running concurrently
Real-World Examples
CVE-2018-1000544 in Ruby's WEBrick server allowed ReDoS through malicious HTTP headers containing specially crafted patterns that caused the regex engine to backtrack exponentially, freezing request processing threads. A single attacker could saturate all available workers.
Cloudflare experienced a global outage in 2019 when a single WAF rule containing an unoptimized regex hit pathological cases on legitimate traffic spikes. The .*(?:.*=.*)* pattern exhibited catastrophic backtracking, consuming CPU cycles across their edge network until the rule was disabled.
CVE-2013-1664 demonstrated XML bomb vulnerabilities in Python's XML libraries. Attackers uploaded XML documents with nested entity definitions-each entity expanding to ten copies of the previous level. A 1KB upload could expand to gigabytes in memory during parsing, crashing applications instantly.
Mitigation
- Strict input validation enforcing size limits, complexity bounds, and nesting depth restrictions before processing
- Request rate limiting per IP address, API key, or user session with exponential backoff
- Timeout enforcement terminating operations exceeding reasonable execution windows (typically 1-5 seconds)
- Resource quotas limiting memory allocation, CPU time, and connection counts per request or tenant
- Regex complexity analysis using linear-time algorithms or sanitizing patterns to eliminate backtracking
- Circuit breakers automatically rejecting requests when error rates or latency thresholds indicate degradation
- Load balancing and autoscaling distributing traffic across instances with automatic capacity expansion
Recent CVEs (36690)
A vulnerability was identified in FascinatedBox lily up to 2.3. Affected by this issue is the function shorthash_for_name of the file src/lily_symtab.c. [CVSS 3.3 LOW]
Client-side denial-of-service in Splunk Enterprise and Splunk Cloud Platform allows low-privileged users to inject malicious payloads through user profile parameters in the authentication REST API endpoint, causing significant page load delays or temporary unresponsiveness of the Splunk Web interface. Affected versions include Splunk Enterprise below 10.2.0, 10.0.2, 9.4.8, 9.3.9, and 9.2.12, and Splunk Cloud Platform below 10.2.2510.3, 10.1.2507.8, 10.0.2503.9, and 9.3.2411.121. No patch is currently available for this vulnerability.
When BIG-IP AFM or BIG-IP DDoS is provisioned, undisclosed traffic can cause TMM to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. [CVSS 7.5 HIGH]
The Linux kernel's ksmbd SMB server implementation contains a denial-of-service vulnerability where failed signature verification on chained SMB2 requests causes an infinite loop due to improper state reset. A local or authenticated attacker can trigger this condition by sending a malformed signed request, causing the ksmbd process to hang and become unresponsive.
In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Validate sp before freeing associated memory System crash with the following signature [154563.214890] nvme nvme2: NVME-FC{1}: controller connect complete [154564.169363] qla2xxx [0000:b0:00.1]-3002:2: nvme: Sched: Set ZIO exchange threshold to 3.
In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Delay module unload while fabric scan in progress System crash seen during load/unload test in a loop.
In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Avoid creating sub-groups asynchronously The asynchronous creation of sub-groups by a delayed work could lead to a NULL pointer dereference when the driver directory is removed before the work completes.
In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Free sp in error path to fix system crash System crash seen during load/unload test in a loop, [61110.449331] qla2xxx [0000:27:00.0]-0042:0: Disabled MSI-X.
In the Linux kernel, the following vulnerability has been resolved: wifi: rtw88: Fix alignment fault in rtw_core_enable_beacon() rtw_core_enable_beacon() reads 4 bytes from an address that is not a multiple of 4. This results in a crash on some systems.
mayswind ezbookkeeping versions 1.2.0 and earlier contain a critical vulnerability in JSON and XML file import processing. [CVSS 6.5 MEDIUM]
Deserialization of Untrusted Data vulnerability in OpenText™ Directory Services allows Object Injection. The vulnerability could lead to remote code execution, denial of service, or privilege escalation.
A flaw has been found in ChaiScript up to 6.1.0. This affects the function chaiscript::Type_Info::bare_equal of the file include/chaiscript/dispatchkit/type_info.hpp. [CVSS 2.5 LOW]
A null pointer dereference in the Linux kernel's loongson-64bit GPIO driver allows local attackers with user privileges to cause a denial of service through an incorrect NULL check that fails to validate chip->irq.parents after memory allocation. The vulnerability affects Linux systems with Loongson GPIO hardware and requires no user interaction to trigger. No patch is currently available.
A vulnerability was detected in ChaiScript up to 6.1.0. The impacted element is the function chaiscript::str_less::operator of the file include/chaiscript/chaiscript_defines.hpp. [CVSS 2.5 LOW]
NVIDIA NeMo Framework contains a vulnerability where an attacker could cause remote code execution by convincing a user to load a maliciously crafted file. A successful exploit of this vulnerability might lead to code execution, denial of service, information disclosure, and data tampering. [CVSS 7.8 HIGH]
NVIDIA NeMo Framework contains a vulnerability where an attacker could cause remote code execution. A successful exploit of this vulnerability might lead to code execution, denial of service, information disclosure, and data tampering. [CVSS 7.8 HIGH]
NVIDIA NeMo Framework contains a vulnerability where an attacker could cause remote code execution. A successful exploit of this vulnerability might lead to code execution, denial of service, information disclosure, and data tampering. [CVSS 7.8 HIGH]
NVIDIA NeMo Framework contains a vulnerability where an attacker could cause remote code execution. A successful exploit of this vulnerability might lead to code execution, denial of service, information disclosure, and data tampering. [CVSS 7.8 HIGH]
A security vulnerability has been detected in ggreer the_silver_searcher versions up to 2.2.0. is affected by improper resource shutdown or release (CVSS 3.3).
Unauthenticated attackers can trigger service restarts through the management API in Aruba Networking Private 5G Core, causing denial of service and disrupting system availability. This network-adjacent vulnerability requires no authentication or user interaction and has a publicly available patch to remediate the issue.
IBM DB2 Merge Backup for Linux, UNIX and Windows 12.1.0.0 could allow an authenticated user to cause the program to crash due to a buffer being overwritten when it is allocated on the stack. [CVSS 6.5 MEDIUM]
Db2 Merge Backup versions up to 12.1.0.0 is affected by incorrect calculation of buffer size (CVSS 6.5).
Db2 contains a vulnerability that allows attackers to an authenticated user to cause a denial of service due to improper neutralizatio (CVSS 6.5).
IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 11.5.0 through 11.5.9 and 12.1.0 through 12.1.3 could allow an authenticated user to cause a denial of service due to improper neutralization of special elements in data query logic
Use After Free vulnerability in Apache Arrow C++. This issue affects Apache Arrow C++ from 15.0.0 through 23.0.0. [CVSS 7.0 HIGH]
Heap buffer overflow in Perl's Crypt::URandom module (versions 0.41-0.54) allows denial of service through integer wraparound when negative length values are passed to the crypt_urandom_getrandom() XS function, causing heap corruption and application crashes. The vulnerability requires direct control over the length parameter, limiting real-world exploitability in typical usage scenarios where this value is hardcoded. No patch is currently available for affected users.
Free5GC versions up to 4.1.0 are vulnerable to denial of service attacks targeting the PFCP UDP Endpoint component, which can be exploited remotely without authentication. Public exploit code exists for this vulnerability, and no patch is currently available, leaving affected deployments at risk of service disruption.
Open5GS 2.7.6 is vulnerable to denial of service through improper handling of S11 session response messages in the MME component, allowing remote unauthenticated attackers to crash the service. Public exploit code exists for this vulnerability, and the vendor has not yet provided a patch despite early notification.
Open5GS versions up to 2.7.6 are vulnerable to a denial of service condition in the SMF component's PDP context request handler, which can be triggered remotely without authentication. An attacker can exploit this reachable assertion flaw to crash the service, and public exploit code is currently available. No patch has been released by the project despite early notification of the issue.
Open5GS versions up to 2.7.6 are vulnerable to a denial of service attack in the SMF component's TFT parsing function when a crafted packet manipulates the traffic filter content length parameter. An unauthenticated remote attacker can trigger this flaw to crash the service, and public exploit code exists with no patch currently available.
The Linux kernel's ice driver contains a race condition in PTP (Precision Time Protocol) handling where periodic work can execute while the Virtual Station Interface (VSI) is being rebuilt, causing a NULL pointer dereference when accessing rx_rings. A local attacker with low privileges can trigger this vulnerability to cause a denial of service by crashing the kernel. No patch is currently available for this medium-severity vulnerability.
Local privilege escalation in the Linux kernel macvlan driver allows a local attacker with user privileges to cause memory corruption and kernel crashes through improper error handling in macvlan_common_newlink(). The vulnerability stems from a use-after-free condition when macvlan link creation fails during device registration, enabling denial of service and potential privilege escalation on affected systems.
The Tegra210-QSPI driver in the Linux kernel is vulnerable to a race condition where an unprotected NULL pointer check in the interrupt handler can be exploited by a local attacker with low privileges to cause a denial of service through kernel panic. The vulnerability occurs when the timeout path clears the curr_xfer pointer while the ISR thread is simultaneously accessing it, resulting in a NULL dereference. A patch is available to resolve this issue by properly synchronizing access with spinlock protection.
In the Linux kernel, the following vulnerability has been resolved: KVM: Don't clobber irqfd routing type when deassigning irqfd When deassigning a KVM_IRQFD, don't clobber the irqfd's copy of the IRQ's routing entry as doing so breaks kvm_arch_irq_bypass_del_producer() on x86 and arm64, which explicitly look for KVM_IRQ_ROUTING_MSI.
In the Linux kernel, the following vulnerability has been resolved: i2c: imx: preserve error state in block data length handler When a block read returns an invalid length, zero or >I2C_SMBUS_BLOCK_MAX, the length handler sets the state to IMX_I2C_STATE_FAILED.
A null pointer dereference in the CephFS kernel client's MDS authentication matching function (ceph_mds_auth_match()) allows local attackers with low privileges to cause a denial of service by crashing the kernel when the mds_namespace mount option is not specified. This regression affects Linux kernel versions 6.18-rc1 and later, impacting systems using CephFS with default mount configurations. No patch is currently available for this vulnerability.
In the Linux kernel, the following vulnerability has been resolved: net: cpsw: Execute ndo_set_rx_mode callback in a work queue Commit 1767bb2d47b7 ("ipv6: mcast: Don't hold RTNL for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP.") removed the RTNL lock for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP operations.
A null pointer dereference in the Linux kernel's mlx5e TC steering driver allows local attackers with user privileges to cause a denial of service by triggering improper flow deletion logic that attempts to access non-existent device peers. The vulnerability occurs when deleting TC flows without validating peer existence, leading to kernel crashes. No patch is currently available for this medium-severity flaw affecting Linux systems with Mellanox network drivers.
The Linux kernel bonding driver contains a use-after-free vulnerability in the slave device initialization path that allows local attackers with user privileges to cause memory corruption or denial of service. The flaw occurs when slave array updates happen before XDP setup completion, enabling the new slave to be used for transmission before being freed by error cleanup handlers. This affects Debian, Ubuntu, and other Linux distributions running vulnerable kernel versions.
A race condition in the Linux kernel's MPTCP address management function allows local attackers with user-level privileges to cause a denial of service through kernel crashes via improper list manipulation without RCU synchronization. The vulnerability exists in mptcp_pm_nl_flush_addrs_doit() where list_splice_init() is called while holding a spinlock, creating unsafe concurrent access conditions. Currently, no patch is available for this medium-severity vulnerability.
A NULL pointer dereference in the Intel ice network driver's ice_vsi_set_napi_queues() function can cause a kernel crash on Linux systems during suspend/resume operations when ring queue vectors are improperly initialized. Local users with standard privileges can trigger this denial of service condition through standard power management operations like systemctl suspend. No patch is currently available for this vulnerability affecting Linux kernel v6.18 and the Intel E810 Ethernet adapter family.
The Linux kernel amdgpu graphics driver crashes with a NULL pointer dereference on APU platforms (Raven, Renoir) when SVM page fault recovery attempts to access uninitialized interrupt ring buffers that only exist on discrete GPUs. A local authenticated attacker can trigger this denial of service by enabling retry faults on affected APUs. No patch is currently available.
A null pointer dereference in the Linux kernel's perf scheduler functionality causes a denial of service when handling user space stacktraces for certain kernel tasks. Local attackers with low privileges can trigger this crash by exploiting inconsistent task classification logic that fails to properly identify user versus kernel tasks. The vulnerability affects the Linux kernel with no patch currently available.
A null pointer dereference in the Linux kernel's gs_usb driver can cause a denial of service when processing malformed USB bulk transfer callbacks, affecting systems with vulnerable CAN interface hardware. Local attackers with unprivileged access can trigger this crash by submitting crafted USB requests that fail resubmission. No patch is currently available for this vulnerability.
A race condition in the Linux kernel's NVMe target bio completion handler can cause a NULL pointer dereference when a bio is re-submitted while simultaneously being deinitialized, leading to denial of service on systems running affected kernel versions. Local attackers with access to NVMe target functionality can trigger this race to crash the kernel. A patch is not currently available.
A race condition in the Linux kernel's Bluetooth HCI UART driver allows local attackers with user privileges to trigger a null pointer dereference and cause a denial of service by initiating a TTY write wakeup during driver initialization. The vulnerability occurs when hci_uart_tx_wakeup() schedules write work before the protocol handler's private data structure is initialized, leading to a crash in hci_uart_write_work(). No patch is currently available for this issue.
The Linux kernel netdevsim driver contains a race condition in the bpf_bound_progs list operations where concurrent calls to nsim_bpf_create_prog() and nsim_bpf_destroy_prog() can corrupt the list and trigger kernel crashes. A local attacker with limited privileges can exploit this vulnerability to cause a denial of service by manipulating eBPF program creation and destruction. No patch is currently available for this issue.
A null pointer dereference in the Linux kernel's SCTP authentication initialization can be triggered by local attackers with user privileges to cause a denial of service through a crash in the packet transmission path. The vulnerability occurs when SCTP-AUTH key setup fails during association peer initialization, leaving a dangling pointer that is subsequently dereferenced. No patch is currently available for this medium-severity issue affecting the Linux kernel.
A NULL pointer dereference in the Linux kernel's ice driver occurs when devlink reload fails and the driver is subsequently removed, affecting systems using Intel ice network adapters. A local privileged user can trigger this denial of service condition by initiating a devlink reinit operation that fails, leaving the hardware in an uninitialized state. The vulnerability stems from a missing ice_deinit_hw() call in the devlink reinit path that leaves control queues uninitialized.
A race condition in the Linux kernel's serial driver allows local attackers with low privileges to bypass TTY device linkage during console configuration, potentially enabling unauthorized access to serial console interfaces on Qualcomm SoCs and other affected systems. The vulnerability stems from improper initialization ordering that fails to configure tty->port before uart_configure_port() is called, creating a window where user-space applications can open the console without proper driver linkage. No patch is currently available.
A Denial of Service (DoS) vulnerability was discovered in the TON Lite Server before v2024.09. [CVSS 7.5 HIGH]
A State Pollution vulnerability was discovered in the TON Virtual Machine (TVM) before v2025.04. The issue exists in the RUNVM instruction logic (VmState::run_child_vm), which is responsible for initializing child virtual machines. [CVSS 7.5 HIGH]
A Stack Overflow vulnerability was discovered in the TON Virtual Machine (TVM) before v2024.10. The vulnerability stems from the improper handling of vmstate and continuation jump instructions, which allow for continuous dynamic tail calls. [CVSS 7.5 HIGH]
A Null Pointer Dereference vulnerability exists in the TON Virtual Machine (TVM) within the TON Blockchain before v2025.06. The issue is located in the execution logic of the INMSGPARAM instruction, where the program fails to validate if a specific pointer is null before accessing it. [CVSS 7.5 HIGH]
Unauthenticated remote attackers can crash BACnet Stack prior to versions 1.5.0rc4 and 1.4.3rc2 by sending a malformed WriteProperty request that triggers an integer underflow during APDU decoding, resulting in an out-of-bounds memory read. Public exploit code exists for this vulnerability. The issue affects embedded systems running vulnerable versions of the BACnet protocol stack library.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority because it is Unused. No vendor patch available.
The BACnet Protocol Stack library versions 1.4.2 and earlier contain an off-by-one buffer overflow in the ubasic interpreter's string tokenizer that crashes the application when processing oversized string literals. Public exploit code exists for this vulnerability, which affects any system running vulnerable versions of the BACnet Stack or Stack Overflow products. An attacker with local access and user interaction can trigger a denial of service condition through a specially crafted input string.
An issue in IObit Unlocker v1.3.0.11 allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 6.2 MEDIUM]
Nessus Agent on Windows systems contains improper file permission controls that allow local authenticated users to trigger denial of service attacks against the agent process. The vulnerability requires local access with standard user privileges and could disrupt security monitoring capabilities on affected hosts. No patch is currently available for this issue.
An improper input validation and protocol compliance vulnerability in free5GC v4.0.1 allows remote attackers to cause a denial of service. The UPF incorrectly accepts a malformed PFCP Association Setup Request, violating 3GPP TS 29.244. [CVSS 7.5 HIGH]
A heap buffer overflow vulnerability in the UPF component of free5GC v4.0.1 allows remote attackers to cause a denial of service via a crafted PFCP Session Modification Request. [CVSS 7.5 HIGH]
An array index out of bounds vulnerability in the AMF component of free5GC v4.0.1 allows remote attackers to cause a denial of service via a crafted 5GS Mobile Identity in a NAS Registration Request message. [CVSS 7.5 HIGH]
A vulnerability has been found in Vnet/IP Interface Package provided by Yokogawa Electric Corporation. If affected product receives maliciously crafted packets, Vnet/IP software stack process may be terminated. [CVSS 6.5 MEDIUM]
A vulnerability has been found in Vnet/IP Interface Package provided by Yokogawa Electric Corporation. If affected product receives maliciously crafted packets, Vnet/IP software stack process may be terminated. [CVSS 6.5 MEDIUM]
A vulnerability has been found in Vnet/IP Interface Package provided by Yokogawa Electric Corporation. If affected product receives maliciously crafted packets, Vnet/IP software stack process may be terminated. [CVSS 6.5 MEDIUM]
A vulnerability has been found in Vnet/IP Interface Package provided by Yokogawa Electric Corporation. If affected product receive maliciously crafted packets, a DoS attack may cause Vnet/IP communication functions to stop or arbitrary programs to be executed. [CVSS 8.2 HIGH]
Improper restriction of operations within the bounds of a memory buffer in PCIe® Link could allow an attacker with access to a guest virtual machine to potentially perform a denial of service attack against the host resulting in loss of availability.
Centova Cast 3.2.12 contains a denial of service vulnerability that allows attackers to overwhelm the system by repeatedly calling the database export API endpoint. Attackers can trigger 100% CPU load by sending multiple concurrent requests to the /api.php endpoint with crafted parameters. [CVSS 7.5 HIGH]
iNetTools for iOS 8.20 contains a denial of service vulnerability in the Whois feature that allows attackers to crash the application by manipulating input. Attackers can paste a specially crafted 98-character buffer into the Domain Name field to trigger an application crash. [CVSS 7.5 HIGH]
SpotAuditor 5.3.2 contains a denial of service vulnerability in its Base64 decryption feature that allows attackers to crash the application by supplying an oversized buffer. [CVSS 7.5 HIGH]
GHIA CamIP 1.2 for iOS contains a denial of service vulnerability in the password input field that allows attackers to crash the application. Attackers can paste a 33-character buffer of repeated characters into the password field to trigger an application crash on iOS devices. [CVSS 7.5 HIGH]
Product Key Explorer 4.2.0.0 contains a denial of service vulnerability that allows local attackers to crash the application by overflowing the registration name input field. [CVSS 6.2 MEDIUM]
SurfOffline Professional 2.2.0.103 contains a structured exception handler (SEH) overflow vulnerability that allows attackers to crash the application by manipulating the project name input. [CVSS 7.5 HIGH]
FTP Navigator 8.03 contains a denial of service vulnerability that allows attackers to crash the application by overwriting Structured Exception Handler (SEH) with malicious input. [CVSS 7.5 HIGH]
XnConvert 1.82 contains a denial of service vulnerability in its registration code input field that allows attackers to crash the application. Attackers can generate a 9000-byte buffer of repeated characters and paste it into the registration code field to trigger an application crash. [CVSS 7.5 HIGH]
ntpd-rs versions prior to 1.7.1 are vulnerable to remote denial of service through crafted NTS (Network Time Protocol Security) packets that force excessive CPU consumption on affected servers. An unauthenticated attacker can exploit this by sending malformed NTS cookie requests that require significantly more processing resources to handle, degrading server performance and availability. The vulnerability affects ntpd-rs deployments with NTS enabled and is resolved in version 1.7.1.
Heap out-of-bounds write in Nav2 AMCL (Adaptive Monte Carlo Localization) in ROS 2 Navigation Framework 1.3.11 and earlier. Robot navigation vulnerability. PoC and patch available.
A reachable infinite loop via an integer wraparound is present in Silicon Labs' Matter SDK which allows an attacker to trigger a denial of service. A hard reset is required to recover the device.
Denial of service in Traefik versions prior to 3.6.8 allows unauthenticated remote attackers to exhaust connection resources by exploiting improper timeout handling in STARTTLS request processing. An attacker can send a PostgreSQL SSLRequest prelude and then stall the connection indefinitely, bypassing the readTimeout protection and accumulating open connections until service availability is degraded. A patch is available in version 3.6.8.