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 (36865)
Unauthenticated remote attackers can crash Palo Alto Networks PAN-OS firewalls through repeated requests, forcing the devices into maintenance mode and causing denial of service. This vulnerability affects Palo Alto firewalls and Prisma Access deployments with no available patch, creating ongoing operational risk. The attack requires no authentication or user interaction and can be exploited over the network.
A heap overflow in the uncv_parse_config() function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted MP4 file. [CVSS 5.5 MEDIUM]
A heap overflow in the ghi_dmx_declare_opid_bin() function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted input. [CVSS 5.5 MEDIUM]
SvelteKit 2.19.0-2.49.4 has SSRF/DoS affecting applications with prerendered routes. Can be exploited to make the server perform arbitrary requests or become unresponsive. Patch available.
Arbitrary code execution in Schneider Electric EcoStruxure Power Build - Rapsody occurs when a user imports a maliciously crafted SSD project file, triggering a use-after-free condition (CWE-416) that yields full confidentiality, integrity and availability impact on the engineering workstation. Exploitation requires the victim to actively open the attacker-supplied file, so it is a client-side/local vector rather than a remotely reachable service. There is no public exploit identified at time of analysis and EPSS probability is very low (0.02%), consistent with a targeted social-engineering delivery rather than mass exploitation.
A Null Pointer Dereference vulnerability exists in the referer header check of the web portal of TP-Link TL-WR841N v14, caused by improper input validation. [CVSS 7.5 HIGH]
A stack overflow in the dump_ttxt_sample function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted packet. [CVSS 7.5 HIGH]
A heap overflow in the avi_parse_input_file() function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted AVI file. [CVSS 6.5 MEDIUM]
Tenda AX-1806 v1.0.0.1 was discovered to contain a stack overflow in the mac parameter of the sub_65B5C function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
A heap overflow in the vorbis_to_intern() function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted .ogg file. [CVSS 5.5 MEDIUM]
A stack overflow in the pcmreframe_flush_packet function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted WAV file. [CVSS 5.5 MEDIUM]
An out-of-bounds read in the GSF demuxer filter component of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted .gsf file. [CVSS 7.5 HIGH]
A stack overflow in the dmx_saf function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted .saf file. [CVSS 5.5 MEDIUM]
A buffer overflow in the vobsub_get_subpic_duration() function of GPAC v2.4.0 allows attackers to cause a Denial of Service (DoS) via a crafted packet. [CVSS 7.5 HIGH]
Cyberfox Web Browser 52.9.1 contains a denial of service vulnerability that allows attackers to crash the application by overflowing the search bar with excessive data. Attackers can generate a 9,000,000 byte payload and paste it into the search bar to trigger an application crash. [CVSS 7.5 HIGH]
Cmder Console Emulator 1.3.18 can be crashed via a malicious .cmd file with repeated characters, causing buffer overflow and DoS. PoC available.
Rdp Manager versions up to 4.9.9.3 is affected by allocation of resources without limits or throttling (CVSS 5.5).
AbsoluteTelnet 11.24 contains a denial of service vulnerability that allows local attackers to crash the application by manipulating username and error report fields. [CVSS 5.5 MEDIUM]
AbsoluteTelnet 11.24 contains a denial of service vulnerability that allows local attackers to crash the application by manipulating DialUp connection and license name fields. [CVSS 5.5 MEDIUM]
Awebserver versions up to 18 is affected by allocation of resources without limits or throttling (CVSS 7.5).
A flaw was found in the libxml2 library. This uncontrolled resource consumption vulnerability occurs when processing XML catalogs that contain repeated <nextCatalog> elements pointing to the same downstream catalog. [CVSS 2.9 LOW]
libxml2's xmlCatalogXMLResolveURI function is vulnerable to uncontrolled recursion when processing self-referencing delegate URI entries in XML catalogs, allowing remote attackers to trigger stack exhaustion and crash applications. This configuration-dependent denial of service requires specially crafted XML input but no authentication, affecting any application using the vulnerable library to parse untrusted catalogs. No patch is currently available.
A flaw was identified in the RelaxNG parser of libxml2 related to how external schema inclusions are handled. The parser does not enforce a limit on inclusion depth when resolving nested <include> directives. [CVSS 3.7 LOW]
Tenda AX-1806 v1.0.0.1 was discovered to contain a stack overflow in the wanSpeed parameter of the sub_65B5C function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Tenda AX-1806 v1.0.0.1 was discovered to contain a stack overflow in the cloneType parameter of the sub_65B5C function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Memory-exhaustion denial of service in Google Keras 3.0.0 through 3.13.0 lets a remote attacker crash the Python interpreter by getting a victim to load a malicious .keras model archive. The crafted archive embeds a valid model.weights.h5 HDF5 file whose dataset declares an enormously large shape, so the weight loader attempts to allocate unbounded memory during deserialization. There is no public exploit identified at time of analysis, EPSS risk is low (0.03%), and a vendor fix is available.
Denial of service conditions in TDC X401GL firmware can be triggered by authenticated network attackers through improper input handling at a system endpoint, resulting in resource exhaustion and service unavailability. The vulnerability requires valid credentials and network access but no user interaction, affecting the availability of affected devices. No patch is currently available for this medium-severity issue.
Denial of service in Wireshark 4.6.0-4.6.2 and 4.4.0-4.4.12 can be triggered through a malformed SOME/IP-SD protocol packet, causing the application to crash. Public exploit code exists for this vulnerability, and affected users should avoid opening untrusted packet captures until a patch is available.
BLF file parser crash in Wireshark 4.6.0 to 4.6.2 and 4.4.0 to 4.4.12 allows denial of service [CVSS 5.5 MEDIUM]
HTTP3 protocol dissector infinite loop in Wireshark 4.6.0 to 4.6.2 allows denial of service [CVSS 4.7 MEDIUM]
Wireshark versions 4.4.0-4.4.12 and 4.6.0-4.6.2 crash when processing malformed IEEE 802.11 wireless packets, enabling a remote denial of service attack that requires user interaction to view the malicious traffic. An attacker can exploit this out-of-bounds write vulnerability by crafting a specially formatted packet, causing the application to become unavailable without requiring authentication. No patch is currently available for this issue.
NVIDIA NSIGHT Graphics for Linux contains a vulnerability where an attacker could cause command injection. A successful exploit of this vulnerability might lead to code execution, escalation of privileges, data tampering, and denial of service. [CVSS 7.8 HIGH]
FreeRDP client before 3.20.1 has a heap buffer overflow in AUDIN format processing. A malicious RDP server can corrupt memory and crash the client. PoC available.
Tenda AX-1806 v1.0.0.1 was discovered to contain a stack overflow in the serverName parameter of the sub_65A28 function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Tenda AX-1806 v1.0.0.1 was discovered to contain a stack overflow in the serviceName parameter of the sub_65A28 function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Prtg Network Monitor versions up to 25.4.114 is affected by uncontrolled resource consumption (CVSS 6.5).
TinyOS versions up to and including 2.1.2 contain a global buffer overflow vulnerability in the printfUART formatted output implementation used within the ZigBee / IEEE 802.15.4 networking stack.
A flaw was found in vsftpd. This vulnerability allows a denial of service (DoS) via an integer overflow in the ls command parameter parsing, triggered by a remote, authenticated attacker sending a crafted STAT command with a specific byte sequence. [CVSS 6.5 MEDIUM]
In the Linux kernel, the following vulnerability has been resolved: drm/msm/dpu: Add missing NULL pointer check for pingpong interface It is checked almost always in dpu_encoder_phys_wb_setup_ctl(), but in a single place the check is missing.
In the Linux kernel, the following vulnerability has been resolved: md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt() The variable mddev->private is first assigned to conf and then checked: conf = mddev->private; if (!conf) ...
In the Linux kernel, the following vulnerability has been resolved: drm/i915/gem: Zero-initialize the eb.vma array in i915_gem_do_execbuffer Initialize the eb.vma array with values of 0 when the eb structure is first set up.
In the Linux kernel, the following vulnerability has been resolved: tracing: Do not register unsupported perf events Synthetic events currently do not have a function to register perf events.
In the Linux kernel, the following vulnerability has been resolved: drm/msm/a6xx: move preempt_prepare_postamble after error check Move the call to preempt_prepare_postamble() after verifying that preempt_postamble_ptr is valid.
In the Linux kernel, the following vulnerability has been resolved: parisc: Do not reprogram affinitiy on ASP chip The ASP chip is a very old variant of the GSP chip and is used e.g. in HP 730 workstations.
In the Linux kernel, the following vulnerability has been resolved: SUNRPC: svcauth_gss: avoid NULL deref on zero length gss_token in gss_read_proxy_verf A zero length gss_token results in pages == 0 and in_token->pages[0] is NULL.
In the Linux kernel, the following vulnerability has been resolved: ACPICA: Avoid walking the Namespace if start_node is NULL Although commit 0c9992315e73 ("ACPICA: Avoid walking the ACPI Namespace if it is not there") fixed the situation when both start_node and acpi_gbl_root_node are NULL, the Linux kernel mainline now still crashed on Honor Magicbook 14 Pro [1].
In the Linux kernel, the following vulnerability has been resolved: um: init cpu_tasks[] earlier This is currently done in uml_finishsetup(), but e.g. with KCOV enabled we'll crash because some init code can call into e.g.
In the Linux kernel, the following vulnerability has been resolved: f2fs: ensure node page reads complete before f2fs_put_super() finishes Xfstests generic/335, generic/336 sometimes crash with the following message: F2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1 ------------[ cut here ]------------ kernel BUG at fs/f2fs/super.c:1939!
In the Linux kernel, the following vulnerability has been resolved: drm/msm: adreno: fix deferencing ifpc_reglist when not declared On plaforms with an a7xx GPU not supporting IFPC, the ifpc_reglist if still deferenced in a7xx_patch_pwrup_reglist() which causes a kernel crash: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 ...
In the Linux kernel, the following vulnerability has been resolved: scs: fix a wrong parameter in __scs_magic __scs_magic() needs a 'void *' variable, but a 'struct task_struct *' is given.
Libsndfile <=1.2.2 contains a memory leak vulnerability in the mpeg_l3_encoder_init() function within the mpeg_l3_encode.c file. [CVSS 5.3 MEDIUM]
Libsoup WebSocket implementations with unset maximum payload size limits are vulnerable to out-of-bounds memory reads during frame processing, potentially exposing sensitive data or causing application crashes. This vulnerability affects applications using non-default WebSocket configurations and requires no user interaction or authentication to exploit. No patch is currently available.
Sysax Multi Server 6.95 crashes when the admin password field receives 800 bytes, causing denial of service. PoC available.
AimOne Video Converter 2.04 Build 103 contains a buffer overflow vulnerability in its registration form that causes application crashes. Attackers can generate a 7000-byte payload to trigger the denial of service and potentially exploit the software's registration mechanism. [CVSS 6.5 MEDIUM]
GuardDog versions prior to 2.7.1 fail to validate decompressed file sizes when extracting Python package archives, enabling denial of service attacks through zip bomb payloads that can consume gigabytes of disk space from minimal compressed data. Public exploit code exists for this vulnerability, affecting users who rely on GuardDog to scan PyPI packages for malicious content. Upgrade to version 2.7.1 or later to remediate this flaw.
Go Ethereum (geth) nodes can be remotely crashed through maliciously crafted network messages, causing denial of service to affected network participants. An unauthenticated attacker on the network can exploit this vulnerability without user interaction to force vulnerable nodes offline. A patch is available in version 1.16.8 and later.
Go Ethereum nodes can be remotely crashed by unauthenticated attackers sending specially crafted network messages, resulting in denial of service. This network-based attack requires no user interaction and affects Golang and Go Ethereum implementations prior to version 1.16.8. A patch is available to remediate this high-severity vulnerability.
Kibana Fleet is vulnerable to denial of service through uncontrolled resource allocation when processing specially crafted bulk retrieval requests, allowing authenticated users with viewer-level privileges to exhaust server memory and crash the application. An attacker can trigger redundant database operations that consume resources without limits, rendering the service unavailable to all users. No patch is currently available for this vulnerability.
Kibana Fleet fails to limit resource allocation when processing specially crafted requests, allowing authenticated attackers to trigger excessive CPU and memory consumption that degrades or completely disables the service. The vulnerability affects Kibana deployments where users have authentication access, and no patch is currently available to remediate the issue.
Denial of Service in Prometheus and Kibana metricsets can be triggered by sending specially crafted malformed payloads to Graphite, Zookeeper, or Prometheus data sources due to improper array index validation and input validation flaws. An unauthenticated attacker on the network can exploit this to crash monitoring services without user interaction. No patch is currently available.
Tarteaucitronjs versions up to 1.29.0 is affected by inefficient regular expression complexity (redos) (CVSS 4.4).
Multiple out-of-bounds read vulnerabilities were identified in a system component responsible for handling certain data buffers. Due to insufficient validation of maximum buffer size values, the process may attempt to read beyond the intended memory region. [CVSS 5.3 MEDIUM]
Multiple out-of-bounds read vulnerabilities were identified in a system component responsible for handling certain data buffers. Due to insufficient validation of maximum buffer size values, the process may attempt to read beyond the intended memory region. [CVSS 5.3 MEDIUM]
Adobe Illustrator versions 29.8.3 and 30.0 and earlier are vulnerable to a null pointer dereference that enables local denial-of-service attacks when users open crafted files. An attacker can crash the application by supplying a malicious file, disrupting workflow for targeted users. No patch is currently available for this vulnerability.
A vulnerability affecting HPE Networking Instant On Access Points has been identified where a device processing a specially crafted packet could enter a non-responsive state, in some cases requiring a hard reset to re-establish services. [CVSS 7.5 HIGH]
Null pointer dereference in the MsgRegisterEvent() system call could allow an attacker with local access and code execution abilities to crash the QNX Neutrino kernel. [CVSS 6.2 MEDIUM]
In the Linux kernel, the following vulnerability has been resolved: ip6_gre: make ip6gre_header() robust Over the years, syzbot found many ways to crash the kernel in ip6gre_header() [1].
In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix the crash issue for zero copy XDP_TX action There is a crash issue when running zero copy XDP_TX action, the crash log is shown below.
In the Linux kernel, the following vulnerability has been resolved: drm/ttm: Avoid NULL pointer deref for evicted BOs It is possible for a BO to exist that is not currently associated with a resource, e.g. because it has been evicted.
Tenda AX-3 v16.03.12.10_CN was discovered to contain a stack overflow in the wanMTU2 parameter of the fromAdvSetMacMtuWan function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Tenda AX-3 v16.03.12.10_CN was discovered to contain a stack overflow in the wanSpeed2 parameter of the fromAdvSetMacMtuWan function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Tenda AX-3 v16.03.12.10_CN was discovered to contain a stack overflow in the cloneType2 parameter of the fromAdvSetMacMtuWan function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Tenda AX-3 v16.03.12.10_CN was discovered to contain a stack overflow in the serviceName2 parameter of the fromAdvSetMacMtuWan function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Tenda AX-3 v16.03.12.10_CN was discovered to contain a stack overflow in the mac2 parameter of the fromAdvSetMacMtuWan function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
Tenda AX-1806 v1.0.0.1 was discovered to contain a stack overflow in the security_5g parameter of the sub_4CA50 function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted request. [CVSS 7.5 HIGH]
In the Linux kernel, the following vulnerability has been resolved: scsi: Revert "scsi: qla2xxx: Perform lockless command completion in abort path" This reverts commit 0367076b0817d5c75dfb83001ce7ce5c64d803a9.
In the Linux kernel, the following vulnerability has been resolved: net/mlx5: fw_tracer, Validate format string parameters Add validation for format string parameters in the firmware tracer to prevent potential security vulnerabilities and crashes from malformed format strings received from firmware.
In the Linux kernel, the following vulnerability has been resolved: ipvs: fix ipv4 null-ptr-deref in route error path The IPv4 code path in __ip_vs_get_out_rt() calls dst_link_failure() without ensuring skb->dev is set, leading to a NULL pointer dereference in fib_compute_spec_dst() when ipv4_link_failure() attempts to send ICMP destination unreachable messages.
In the Linux kernel, the following vulnerability has been resolved: media: iris: Add sanity check for stop streaming Add sanity check in iris_vb2_stop_streaming. If inst->state is already IRIS_INST_ERROR, we should skip the stream_off operation because it would still send packets to the firmware.
In the Linux kernel, the following vulnerability has been resolved: platform/chrome: cros_ec_ishtp: Fix UAF after unbinding driver After unbinding the driver, another kthread `cros_ec_console_log_work` is still accessing the device, resulting an UAF and crash.
In the Linux kernel, the following vulnerability has been resolved: net/hsr: fix NULL pointer dereference in prp_get_untagged_frame() prp_get_untagged_frame() calls __pskb_copy() to create frame->skb_std but doesn't check if the allocation failed.
In the Linux kernel, the following vulnerability has been resolved: inet: frags: flush pending skbs in fqdir_pre_exit() We have been seeing occasional deadlocks on pernet_ops_rwsem since September in NIPA.
Service Workers in Mozilla Firefox and Thunderbird versions below 147 are vulnerable to remote denial-of-service attacks that require no user interaction or authentication. An unauthenticated attacker can crash affected applications over the network, and public exploit code exists for this vulnerability. Currently no patch is available for remediation.
Denial of service in Siemens SIMATIC ET 200 family PROFINET interface modules and PN/PN couplers allows remote unauthenticated attackers to render industrial controllers unresponsive by sending a single malformed S7 protocol Disconnect Request to TCP/102. The CVSS 4.0 score of 8.7 reflects the network-reachable, no-privileges-required vector against availability-critical OT assets, though EPSS is only 0.02% and no public exploit has been identified at time of analysis. Recovery requires a physical power cycle, which is operationally severe in plant environments.
Denial of service in Ollama's multi-modal image processing (versions 0.11.5-rc0 through 0.13.5) lets remote attackers crash the model runner by POSTing crafted base64 image data to the /api/chat endpoint. The decoded data is passed to mtmd_helper_bitmap_init_from_buf without validating that it is valid media; the function returns NULL on malformed input and the unchecked pointer is dereferenced, triggering a segmentation fault that takes the model offline for all users until restart. Rated CVSS 4.0 8.7 (availability-only impact); publicly available exploit code exists via a Huntr bounty, but EPSS is low (0.09%, 25th percentile) and it is not on CISA KEV.
Denial-of-service in LangChain versions up to and including 0.3.1 lets remote attackers exhaust CPU by feeding a crafted string into the MRKLOutputParser.parse() method, whose backtracking-prone regular expression exhibits catastrophic backtracking (ReDoS). Because MRKL agents parse LLM output to extract tool actions, an attacker who can influence that text - typically via prompt injection in downstream applications - can stall or hang the parsing thread. Publicly available exploit code exists (huntr bounty), though EPSS is low at 0.08% and it is not on the CISA KEV list.
Denial-of-service in LlamaIndex (run-llama/llama_index) versions up to and including 0.12.2 lets remote unauthenticated attackers exhaust CPU and memory through the VannaPack VannaQueryEngine. The engine's custom_query() converts a user-supplied natural-language prompt into SQL and runs it via vn.run_sql() with no execution limits, so a crafted prompt can produce an unbounded or extremely expensive query. Publicly available exploit code exists (Huntr bounty report), though EPSS is low at 0.12% (30th percentile) and it is not listed in CISA KEV.
cpp-httplib versions prior to 0.30.1 are vulnerable to denial of service attacks due to insufficient validation of decompressed HTTP request body sizes. An unauthenticated remote attacker can send a malicious gzip or brotli-compressed request that decompresses to an arbitrarily large payload in memory, exhausting server resources. Public exploit code exists for this vulnerability, and a patch is available in version 0.30.1 and later.
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In 0.9-rc2 and earlier, avahi-daemon can be crashed by sending 2 unsolicited announcements with CNAME resource records 2 seconds apart. [CVSS 6.5 MEDIUM]
Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In 0.9-rc2 and earlier, avahi-daemon can be crashed by sending unsolicited announcements containing CNAME resource records pointing it to resource records with short TTLs. [CVSS 6.5 MEDIUM]