CVE-2025-21091 is a high-severity vulnerability affecting multiple F5 BIG-IP products. This vulnerability allows for undisclosed requests to increase memory resource utilization when SNMP v1 or v2c are disabled. The CVSS score for this vulnerability is 8.7, indicating a significant threat to organizations using affected F5 products.
Risk to organizations includes potential service degradation due to high memory usage, which can impact availability. Given the critical nature of many applications running on BIG-IP devices, this vulnerability poses a substantial risk. Organizations should prioritize patching immediately.
The vulnerability was published on February 5, 2025, and remains under analysis as of October 21, 2025. While there are no known exploits reported, the vulnerability's high CVSS score emphasizes the importance of immediate action from security teams.
In light of this vulnerability, organizations using F5 BIG-IP products should assess their current configurations and ensure they are up to date with available patches.
Vulnerability Details
When SNMP v1 or v2c are disabled on the BIG-IP, undisclosed requests can cause an increase in memory resource utilization. Software versions that have reached End of Technical Support (EoTS) are not evaluated. The vulnerability is classified under CWE-401.
Technical Analysis
The attack vector for CVE-2025-21091 is network-based, with low attack complexity. No privileges or user interaction are required for exploitation. The primary impact is on availability, which can lead to potential service disruption if not addressed.
Risk & Impact Analysis
Real-world deployment of this vulnerability can result in significant operational impacts. Organizations utilizing affected F5 products are at risk of increased memory usage leading to potential outages. Given the high CVSS score of 8.7, organizations should address this vulnerability in their priority patch cycle.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions include F5 BIG-IP products, specifically versions 15.1.0 to 15.1.10, 16.1.0 to 16.1.6, and 17.1.0 to 17.1.2 across various components.
Mitigation & Remediation
Organizations must immediately update their F5 BIG-IP products to the latest patched versions to mitigate this vulnerability. Regular monitoring and configuration audits are recommended to ensure that the most secure configurations are applied. For more detailed guidance, organizations can refer to the application security assessment procedures.
Detection Guidance
Monitoring for memory resource utilization anomalies can help detect potential exploitation attempts. Inspecting logs for unusual SNMP-related requests may indicate attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-21091 highlights the need for organizations to maintain updated configurations and actively manage their security posture. This vulnerability represents a growing trend of resource exploitation vulnerabilities in network devices. Security teams should take this as a strategic opportunity to enhance their defenses against similar vulnerabilities. For further insights, consider reading our article on vulnerability management program design and how it can bolster security strategies.
Additionally, our resources on penetration testing methodology and continuous security testing can further assist in fortifying defenses against emerging threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
.webp)