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 (5577)
A buffer overflow vulnerability has been discovered in the Netis WF2880 v2.1.40207 in the FUN_004743f8 function of the cgitest.cgi file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A buffer overflow vulnerability has been discovered in Netis WF2880 v2.1.40207 in the FUN_00473154 function of the cgitest.cgi file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A buffer overflow vulnerability has been discovered in Netis WF2880 v2.1.40207 in the FUN_00476598 function of the cgitest.cgi file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A buffer overflow vulnerability has been discovered in Netis WF2880 v2.1.40207 in the Function_00465620 of the cgitest.cgi file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A buffer overflow vulnerability has been discovered in Netis WF2880 v2.1.40207 in the FUN_00471994 function of the cgitest.cgi file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Netty is an asynchronous, event-driven network application framework. Rated high severity (CVSS 8.2), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An HTTP/2 implementation flaw allows a denial-of-service (DoS) that uses malformed HTTP/2 control frames in order to break the max concurrent streams limit (HTTP/2 MadeYouReset Attack). Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
When a BIG-IP LTM Client SSL profile is configured on a virtual server with SSL Forward Proxy enabled and Anonymous Diffie-Hellman (ADH) ciphers enabled, undisclosed requests can cause the Traffic. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A null pointer dereference vulnerability was discovered in Netis WF2780 v2.2.35445. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
ImageMagick is free and open-source software used for editing and manipulating digital images. Rated medium severity (CVSS 6.1), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Allocation of Resources Without Limits or Throttling vulnerability in Legion of the Bouncy Castle Inc. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability has been found in INSTAR 2K+ and 4K 3.11.1 Build 1124. Rated high severity (CVSS 7.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
The Database for Contact Form 7, WPforms, Elementor forms plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 1.4.3 via deserialization of untrusted input. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Use after free in Aura in Google Chrome prior to 139.0.7258.127 allowed a remote attacker who convinced a user to engage in specific UI gestures to potentially exploit heap corruption via a crafted. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Adobe Framemaker versions 2020.8, 2022.6 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Adobe Framemaker versions 2020.8, 2022.6 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Adobe Framemaker versions 2020.8, 2022.6 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Adobe Framemaker versions 2020.8, 2022.6 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
InDesign Desktop versions 20.4, 19.5.4 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
InDesign Desktop versions 20.4, 19.5.4 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
InDesign Desktop versions 20.4, 19.5.4 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
InCopy versions 20.4, 19.5.4 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Animate versions 23.0.12, 24.0.9 and earlier are affected by a Use After Free vulnerability that could lead to disclosure of sensitive memory. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Animate versions 23.0.12, 24.0.9 and earlier are affected by a Use After Free vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office PowerPoint allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office Word allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office Visio allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Use after free in Microsoft Office Visio allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Uncontrolled resource consumption in Windows Remote Desktop Services allows an unauthorized attacker to deny service over a network. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Epss exploitation probability 10.2% and no vendor patch available.
Use after free in Windows Connected Devices Platform Service allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.0). No vendor patch available.
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.0). No vendor patch available.
Null pointer dereference in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Null pointer dereference in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Use after free in Desktop Windows Manager allows an authorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Use after free in Windows Kernel allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.0). No vendor patch available.
Use after free in Microsoft Brokering File System allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.0). No vendor patch available.
Null pointer dereference in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Use after free in Kernel Transaction Manager allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.0). No vendor patch available.
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.0). No vendor patch available.
Use after free in Windows PrintWorkflowUserSvc allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8). No vendor patch available.
Use after free in Windows Message Queuing allows an unauthorized attacker to execute code over a network. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
Allocation of resources without limits or throttling in Windows DirectX allows an authorized attacker to deny service over a network. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Epss exploitation probability 14.9% and no vendor patch available.
Use after free in Remote Access Point-to-Point Protocol (PPP) EAP-TLS allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.3), this vulnerability is low attack complexity. No vendor patch available.
Use after free in Desktop Windows Manager allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Use after free in Windows Kernel allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Adobe Commerce versions 2.4.9-alpha1, 2.4.8-p1, 2.4.7-p6, 2.4.6-p11, 2.4.5-p13, 2.4.4-p14 and earlier are affected by an Improper Input Validation vulnerability that could lead to application. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Illustrator versions 28.7.8, 29.6.1 and earlier are affected by a Use After Free vulnerability that could lead to disclosure of sensitive memory. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Illustrator versions 28.7.8, 29.6.1 and earlier are affected by a NULL Pointer Dereference vulnerability that could lead to application denial-of-service. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Exposure of sensitive information to an unauthorized actor for some Edge Orchestrator software before version 24.11.1 for Intel(R) Tiber(TM) Edge Platform may allow an authenticated user to. Rated low severity (CVSS 2.1). No vendor patch available.
Uncontrolled resource consumption for some Edge Orchestrator software before version 24.11.1 for Intel(R) Tiber(TM) Edge Platform may allow an unauthenticated user to potentially enable denial of. Rated low severity (CVSS 2.1), this vulnerability is no authentication required. No vendor patch available.
Uncontrolled resource consumption for some Edge Orchestrator software before version 24.11.1 for Intel(R) Tiber(TM) Edge Platform may allow an authenticated user to potentially enable denial of. Rated medium severity (CVSS 5.1), this vulnerability is low attack complexity. No vendor patch available.
Uncontrolled resource consumption in the Linux kernel-mode driver for some Intel(R) 700 Series Ethernet before version 2.28.5 may allow an authenticated user to potentially enable denial of service. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. No vendor patch available.
Uncontrolled resource consumption in the Linux kernel-mode driver for some Intel(R) 700 Series Ethernet before version 2.28.5 may allow an authenticated user to potentially enable denial of service. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. No vendor patch available.
Uncontrolled resource consumption for some Edge Orchestrator software before version 24.11.1 for Intel(R) Tiber(TM) Edge Platform may allow an authenticated user to potentially enable denial of. Rated medium severity (CVSS 5.9), this vulnerability is low attack complexity. No vendor patch available.
Protection mechanism failure in the Intel(R) Graphics Driver for the Intel(R) Arc(TM) B-Series graphics before version 32.0.101.6737 may allow an authenticated user to potentially enable denial of. Rated medium severity (CVSS 4.1), this vulnerability is low attack complexity. No vendor patch available.
Protection mechanism failure for some Edge Orchestrator software before version 24.11.1 for Intel(R) Tiber(TM) Edge Platform may allow an authenticated user to potentially enable denial of service. Rated medium severity (CVSS 5.1), this vulnerability is low attack complexity. No vendor patch available.
NULL pointer dereference for some Intel(R) Graphics Drivers may allow an authenticated user to potentially enable denial of service via local access. Rated medium severity (CVSS 6.8), this vulnerability is low attack complexity. No vendor patch available.
Improper access control for some Device Plugins for Kubernetes software maintained by Intel before version 0.32.0 may allow a privileged user to potentially enable denial of service via local access. Rated medium severity (CVSS 6.7), this vulnerability is low attack complexity. No vendor patch available.
Improper input validation in some firmware for the Intel(R) E810 Ethernet before version 4.6 may allow a privileged user to enable denial of service via local access. Rated medium severity (CVSS 5.1), this vulnerability is low attack complexity. No vendor patch available.
Integer overflow or wraparound in the Linux kernel-mode driver for some Intel(R) 800 Series Ethernet before version 1.17.2 may allow an authenticated user to potentially enable denial of service via. Rated high severity (CVSS 8.4), this vulnerability is low attack complexity. No vendor patch available.
Missing reference to active allocated resource for some Intel(R) Xeon(R) processors may allow an authenticated user to potentially enable denial of service via local access. Rated medium severity (CVSS 4.1), this vulnerability is low attack complexity. No vendor patch available.
Improper conditions check for some Intel(R) PROSet/Wireless WiFi Software for Windows before version 23.110.0.5 may allow an unauthenticated user to potentially enable denial of service via adjacent. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Untrusted Pointer Dereference for some Intel(R) QuickAssist Technology software before version 2.5.0 may allow an authenticated user to potentially enable denial of service via local access. Rated medium severity (CVSS 6.8), this vulnerability is low attack complexity. No vendor patch available.
Missing release of memory after effective lifetime in the UEFI OobRasMmbiHandlerDriver module for some Intel(R) reference server platforms may allow a privileged user to enable denial of service via. Rated medium severity (CVSS 5.6). No vendor patch available.
Uncontrolled recursion for some TinyCBOR libraries maintained by Intel(R) before version 0.6.1 may allow an authenticated user to potentially enable denial of service via local access. Rated medium severity (CVSS 4.1). No vendor patch available.
Hydra is a continuous integration service for Nix based projects. Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Missing Authentication for Critical Function vulnerability could allow attackers to access critical functionality without authentication.
XEE in Ivanti Connect Secure before 22.7R2.8 or 22.8R2, Ivanti Policy Secure before 22.7R1.5, Ivanti ZTA Gateway before 22.8R2.3-723 and Ivanti Neurons for Secure Access before 22.8R1.4 (Fix deployed. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A heap-based buffer overflow in Ivanti Connect Secure before 22.7R2.8 or 22.8R2, Ivanti Policy Secure before 22.7R1.5, Ivanti ZTA Gateway before 22.8R2.3-723 and Ivanti Neurons for Secure Access. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A buffer over-read vulnerability in Ivanti Connect Secure before 22.7R2.8 or 22.8R2, Ivanti Policy Secure before 22.7R1.5, Ivanti ZTA Gateway before 2.8R2.3-723 and Ivanti Neurons for Secure Access. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
EDK2 contains a vulnerability in BIOS where a user may cause an Integer Overflow or Wraparound by network means. Rated medium severity (CVSS 6.3), this vulnerability is low attack complexity. No vendor patch available.
APTIOV contains a vulnerability in BIOS where a skilled user may cause “Race Condition” by local access. Rated high severity (CVSS 7.3), this vulnerability is low attack complexity. No vendor patch available.
A vulnerability has been identified in SINEC Traffic Analyzer (6GK8822-1BG01-0BA0) (All versions < V3.0). Rated medium severity (CVSS 6.8), this vulnerability is low attack complexity. No vendor patch available.
A vulnerability has been identified in SIPROTEC 5 6MD84 (CP300) (All versions < V10.0), SIPROTEC 5 6MD85 (CP300) (All versions >= V7.80 < V10.0), SIPROTEC 5 6MD86 (CP300) (All versions >= V7.80 <. Rated low severity (CVSS 2.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A vulnerability has been identified in SIMATIC RTLS Locating Manager (All versions < V3.3). Rated medium severity (CVSS 6.9), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A vulnerability has been identified in SIPROTEC 4 6MD61 (All versions), SIPROTEC 4 6MD63 (All versions), SIPROTEC 4 6MD66 (All versions), SIPROTEC 4 6MD665 (All versions), SIPROTEC 4 7SA522 (All. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A Denial Of Service via File Upload (DOS) vulnerability in the Liferay Portal 7.4.3.0 through 7.4.3.132, and Liferay DXP 2025.Q1.0 through 2025.Q1.8, 2024.Q4.0 through 2024.Q4.7, 2024.Q3.0 through. Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Allocation of Resources Without Limits or Throttling vulnerability in Legion of the Bouncy Castle Inc. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight. Rated high severity (CVSS 8.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Mattermost Confluence Plugin version <1.5.0 fails to handle unexpected request body which allows attackers to crash the plugin via constant hit to create channel subscription endpoint with an invalid. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Mattermost Confluence Plugin version <1.5.0 fails to handle unexpected request body which allows attackers to crash the plugin via constant hit to server webhook endpoint with an invalid request body. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
Mattermost Confluence Plugin version <1.5.0 fails to handle unexpected request body which allows attackers to crash the plugin via constant hit to server webhook endpoint with an invalid request body. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
Mattermost Confluence Plugin version <1.5.0 fails to handle unexpected request body which allows attackers to crash the plugin via constant hit to update channel subscription endpoint with an invalid. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
The YugabyteDB tablet server contains a flaw in its YCQL query handling that can trigger a null pointer dereference when processing certain malformed inputs. Rated medium severity (CVSS 4.1). No vendor patch available.
A vulnerability was determined in NASM Netwide Assember 2.17rc0. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability has been found in NASM Netwide Assember 2.17rc0. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.