CVE-2020-5902
CRITICALCVE-2020-5902 is a critical-severity (CVSS 9.8) Path Traversal vulnerability in f5 big-ip access policy manager. It is in CISA's Known Exploited Vulnerabilities catalog (added 2021-11-03) and has been used in ransomware campaigns — treat it as actively exploited and patch now. O3 Security detects and blocks CVE-2020-5902 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.
In BIG-IP versions 15.0.0-15.1.0.3, 14.1.0-14.1.2.5, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.1, the Traffic Management User Interface (TMUI), also referred to as the Configuration…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2021-11-03 — including use in ransomware campaigns. Federal agencies were required to remediate by 2022-05-03.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2020-5902.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2020-5902 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Description
In BIG-IP versions 15.0.0-15.1.0.3, 14.1.0-14.1.2.5, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.1, the Traffic Management User Interface (TMUI), also referred to as the Configuration utility, has a Remote Code Execution (RCE) vulnerability in undisclosed pages.
Affected Products
big-ip access policy managerf5big-ip advanced firewall managerf5big-ip advanced web application firewallf5big-ip analyticsf5big-ip application acceleration managerf5big-ip application security managerf5Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
BIG-IP 15.0.0 < 15.1.0.3 / 14.1.0 < 14.1.2.5 / 13.1.0 < 13.1.3.3 / 12.1.0 < 12.1.5.1 / 11.6.1 < 11.6.5.1 - Traffic Management User Interface 'TMUI' Remote Code Execution
by Critical Start · Jul 6, 2020
F5 Big-IP 13.1.3 Build 0.0.6 - Local File Inclusion
by Carlos E. Vieira · Jul 26, 2020
BIG-IP 15.0.0 < 15.1.0.3 / 14.1.0 < 14.1.2.5 / 13.1.0 < 13.1.3.3 / 12.1.0 < 12.1.5.1 / 11.6.1 < 11.6.5.1 - Traffic Management User Interface 'TMUI' Remote Code Execution (PoC)
by Budi Khoirudin · Jul 5, 2020
Detection & mitigation playbook
Vendor / applianceDetect
Inventory every f5 big-ip access policy manager deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the f5 big-ip access policy manager security patch or hotfix for CVE-2020-5902 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2020-5902 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2020-5902. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2020-5902 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2020-5902 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.