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 (40225)
An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service by leveraging a long-running operation that exists to support restartability of PTE updates. Rated medium severity (CVSS 6.5), this vulnerability is low attack complexity.
An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging incorrect use of the HVM physmap concept for PV domains. Rated medium severity (CVSS 6.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging a race condition that arose when XENMEM_exchange was. Rated high severity (CVSS 7.0).
An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service or gain privileges by leveraging a page-writability race condition during addition of a. Rated high severity (CVSS 7.8).
An issue was discovered in Xen through 4.11.x allowing x86 guest OS users to cause a denial of service or gain privileges because grant-table transfer requests are mishandled. Rated high severity (CVSS 8.8), this vulnerability is low attack complexity. No vendor patch available.
An issue was discovered in drivers/xen/balloon.c in the Linux kernel before 5.2.3, as used in Xen through 4.12.x, allowing guest OS users to cause a denial of service because of unrestricted resource. Rated medium severity (CVSS 6.5), this vulnerability is low attack complexity. This Allocation of Resources Without Limits vulnerability could allow attackers to exhaust system resources through uncontrolled allocation.
An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a compare-and-exchange operation. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
The WebRTC component in the Signal Private Messenger application through 4.47.7 for Android processes videoconferencing RTP packets before a callee chooses to answer a call, which might make it. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in Pillow before 6.2.0. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Foxit Reader before 9.7 allows an Access Violation and crash if insufficient memory exists. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Valve Steam Client before 2019-09-12 allows placing or appending partially controlled filesystem content, as demonstrated by file modifications on Windows in the context of NT AUTHORITY\SYSTEM. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
FON2601E-SE, FON2601E-RE, FON2601E-FSW-S, and FON2601E-FSW-B with firmware versions 1.1.7 and earlier contain an issue where they may behave as open resolvers. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A double free vulnerability in the DDGifSlurp function in decoding.c in the android-gif-drawable library before version 1.2.18, as used in WhatsApp for Android before version 2.19.244 and many other. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Unbound before 1.9.4 accesses uninitialized memory, which allows remote attackers to trigger a crash via a crafted NOTIFY query. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
sf-pcapng.c in libpcap before 1.9.1 does not properly validate the PHB header length before allocating memory. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Allocation of Resources Without Limits vulnerability could allow attackers to exhaust system resources through uncontrolled allocation.
rpcapd/daemon.c in libpcap before 1.9.1 allows attackers to cause a denial of service (NULL pointer dereference and daemon crash) if a crypt() call fails. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
A vulnerability in the Internet Key Exchange version 1 (IKEv1) feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an. Rated high severity (CVSS 8.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
JetBrains PyCharm before 2019.2 was allocating a buffer of unknown size for one of the connection processes. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the web-based management interface of Cisco IC3000 Industrial Compute Gateway could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A vulnerability in the web-based interface of Cisco Unified Communications Manager and Cisco Unified Communications Manager Session Management Edition (SME) could allow an unauthenticated, remote. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the configuration of the Pluggable Authentication Module (PAM) used in Cisco Firepower Threat Defense (FTD) Software, Cisco Firepower Management Center (FMC) Software, and Cisco. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A vulnerability in the WebVPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the Secure Copy (SCP) feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A vulnerability in the Session Initiation Protocol (SIP) inspection module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the Secure Sockets Layer (SSL) VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A vulnerability in the Open Shortest Path First (OSPF) implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an. Rated high severity (CVSS 7.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the FTP inspection engine of Cisco Adaptive Security (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In a rare scenario, Check Point R80.30 Security Gateway before JHF Take 50 managed by Check Point R80.30 Management crashes with a unique configuration of enhanced logging. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in write_tpt_entry in drivers/infiniband/hw/cxgb4/mem.c in the Linux kernel through 5.3.2. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
PuTTY before 0.73 might allow remote SSH-1 servers to cause a denial of service by accessing freed memory locations via an SSH1_MSG_DISCONNECT message. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
PuTTY before 0.73 on Windows improperly opens port-forwarding listening sockets, which allows attackers to listen on the same port to steal an incoming connection. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Catalog.cc in Xpdf 4.02 has a NULL pointer dereference because Catalog.pageLabels is initialized too late in the Catalog constructor. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
BT process died and BT toggled due to null pointer dereference when invalid vendor pass through command sent from remote in Snapdragon Auto, Snapdragon Consumer IOT, Snapdragon Mobile, Snapdragon. Rated high severity (CVSS 8.2), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Possible use after free issue due to improper input validation in volume listener library in Snapdragon Auto, Snapdragon Compute, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Use after free issue occurs If another instance of open for voice_svc node has been called from application without closing the previous one. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Possible null-pointer dereference can occur while parsing avi clip during copy in Snapdragon Auto, Snapdragon Compute, Snapdragon Consumer IOT, Snapdragon Industrial IOT, Snapdragon IoT, Snapdragon. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In the Linux kernel before 5.0.3, a memory leak exits in hsr_dev_finalize() in net/hsr/hsr_device.c if hsr_add_port fails to add a port, which may cause denial of service, aka CID-6caabe7f197d. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
In the Linux kernel before 5.0, a memory leak exists in sit_init_net() in net/ipv6/sit.c when register_netdev() fails to register sitn->fb_tunnel_dev, which may cause denial of service, aka. Rated medium severity (CVSS 4.7). Public exploit code available.
In Bluetooth, there is a possible out of bounds read due to an incorrect bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible out of bounds read due to a use after free. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible null pointer dereference due to a missing null check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible information disclosure due to a use after free. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In Bluetooth, there is a possible out of bounds read due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In libhevc, there is a possible out of bounds read due to an integer overflow. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In libstagefright, there is a possible resource exhaustion due to a missing bounds check. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible null pointer dereference due to a missing null check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is possible controlled termination due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible out of bounds read due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible out of bounds read due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In netd, there is a possible out of bounds read due to a use after free. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In libstagefright, there is a possible resource exhaustion due to a missing bounds check. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Account of Account.java, there is a possible boot loop due to improper input validation. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In JobStore, there is a mismatched serialization/deserialization for the "battery-not-low" job attribute. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In libskia, there is a possible crash due to a missing null check. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In libvpx, there is a possible resource exhaustion due to improper input validation. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In libstagefright, there is a possible resource exhaustion due to a missing bounds check. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Keymaster, there is a possible EoP due to a use after free. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
In libstagefright, there is a possible resource exhaustion due to improper input validation. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In libstagefright, there is a possible resource exhaustion due to improper input validation. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In the m4v_h263 codec, there is a possible out of bounds read due to a use after free. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In Bluetooth, there is a possible crash due to an integer overflow. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible remote code execution due to an improper memory allocation. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Bluetooth, there is a possible out of bounds read due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In AAC Codec, there is a possible resource exhaustion due to improper input validation. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In the wifi hotspot service, there is a possible denial of service due to a null pointer dereference. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In the Bluetooth stack, there is a possible out of bounds write due to a use after free. Rated medium severity (CVSS 6.7), this vulnerability is low attack complexity. No vendor patch available.
It is possible to delete an IndexedDB key value and subsequently try to extract it during conversion. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A type confusion vulnerability exists in Spidermonkey, which results in a non-exploitable crash. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A use-after-free vulnerability can occur while manipulating video elements if the body is freed while still in use. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
IBM MQ 7.1.0.0 - 7.1.0.9, 7.5.0.0 - 7.5.0.9, 8.0.0.0 - 8.0.0.11, 9.0.0.0 - 9.0.0.6, 9.1.0.0 - 9.1.0.2, and 9.1.1 - 9.1.2 is vulnerable to a denial of service attack caused by a memory leak in the. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity.
A denial of service vulnerability was reported in Lenovo System Update versions prior to 5.07.0088 that could allow configuration files to be written to non-standard locations. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
In Apache HTTP Server 2.4.32-2.4.39, when mod_remoteip was configured to use a trusted intermediary proxy server using the "PROXY" protocol, a specially crafted PROXY header could trigger a stack. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
In Apache Subversion versions up to and including 1.9.10, 1.10.4, 1.12.0, Subversion's svnserve server process may exit when a client sends certain sequences of protocol commands. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This NULL Pointer Dereference vulnerability could allow attackers to crash the application by dereferencing a null pointer.
IBM MQ 7.5.0.0 - 7.5.0.9, 7.1.0.0 - 7.1.0.9, 8.0.0.0 - 8.0.0.12, 9.0.0.0 - 9.0.0.6, 9.1.0.0 - 9.1.0.2, and 9.1.0 - 9.1.2 command server is vulnerable to a denial of service attack caused by an. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A flaw was found in, Fedora versions of krb5 from 1.16.1 to, including 1.17.x, in the way a Kerberos client could crash the KDC by sending one of the RFC 4556 "enctypes". Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
In Rubyzip before 1.3.0, a crafted ZIP file can bypass application checks on ZIP entry sizes because data about the uncompressed size can be spoofed. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A vulnerability in the RADIUS Change of Authorization (CoA) code of Cisco TrustSec, a feature within Cisco IOS XE Software, could allow an unauthenticated, remote attacker to cause a denial of. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the Cisco TrustSec (CTS) Protected Access Credential (PAC) provisioning module of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an. Rated high severity (CVSS 8.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the HTTP server code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the HTTP server to crash. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the filesystem resource management code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to exhaust filesystem resources on an affected device and cause a. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in Unified Threat Defense (UTD) in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the IOx application environment of multiple Cisco platforms could allow an unauthenticated, remote attacker to cause the IOx web server to stop processing HTTPS requests, resulting. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.