CriticalCVE-2020-5902

    F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution Vulnerability (CVE-2020-5902)

    Published In CISA KEV since Sources: SingCERT, CVE.org

    What is affected, what to do

    CVE-2020-5902 is a remote code execution (RCE) vulnerability in the F5 BIG-IP Traffic Management User Interface (TMUI). An attacker can gain full control of the system without authentication. This vulnerability is actively exploited in ransomware campaigns since 2021 and affects specific versions of BIG-IP. Immediate patching to the latest versions is critical to mitigate the risk.

    The vulnerability is being actively exploited; treat it as a priority. CISA lists it as used in ransomware campaigns. Update big-ip_access_policy_manager to version 15.1.0.4, big-ip_advanced_firewall_manager to version 13.1.3.4, big-ip_advanced_web_application_firewall to version 12.1.5.2. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • BIG-IP eq 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..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

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    Metrics

    9.8

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: SingCERT, CVE.org

    —

    EPSS score

    No value is available for this vulnerability.

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    254.00 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    actively exploitedSource: ANSSI / CERT-FR How we classify
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    9.8 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.8
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 29 January 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-22

    Response and mitigation

    Why act now?

    Prioritisation rationale

    This is one of the most heavily abused perimeter RCEs of the past several years: unauthenticated remote code execution over TMUI, network-reachable without credentials, and trivially weaponised through public PoCs available since July 2020. CISA flags active ransomware use and the exploitation likelihood sits at the very top of the EPSS scale. Typical targets are internet-exposed BIG-IPs — common at banks, government, telcos and other KRITIS operators where the appliance acts as TLS termination or WAF. For any NIS2-regulated organisation, every BIG-IP with TMUI at the perimeter is a P1 item, and even an apparently patched device requires retrospective compromise assessment back to 2020 before the ticket can be closed.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Install the F5 hotfix: upgrade to one of the fixed releases listed in F5 advisory K52145254 — 15.1.0.4, 14.1.2.6, 13.1.3.4, 12.1.5.2 or 11.6.5.2. Plan for a reboot and patch HA pairs sequentially.
      • Remove TMUI/Configuration Utility from the internet immediately: set Self-IP port-lockdown to "Allow None" (tmsh modify net self <self> allow-service none) and restrict the management interface to a dedicated admin VLAN or VPN only.
      • Apply the F5 interim httpd workaround until patched: add the LocationMatch blocks for ; and hsqldb to /config/httpd/conf/httpd.conf, run tmsh restart sys service httpd, then tmsh save sys config.
      • Rotate credentials: admin, root and API tokens on any BIG-IP appliance that has ever been exposed since July 2020. Treat SNMP communities, iControl REST keys and F5 SSH keys as compromised until forensics proves otherwise.
      • Run forensic triage in parallel with patching: preserve /var/log/audit, /var/log/restjavad.0.log, /var/log/tomcat/catalina.out and /var/log/httpd/*, hunting for requests against /tmui/login.jsp/..;/, /hsqldb and tmsh invocations by the nobody/apache user.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: expose TMUI (HTTPS 443 on management IP and Self-IPs) only from a jumphost segment; block TCP 443 to BIG-IP management addresses at the perimeter permanently — even if the appliance load-balances port 443 for backends, TMUI itself does not belong on the data plane.
      • WAF/reverse proxy in front of TMUI: drop requests containing ; in the path, ..;/, /tmui/login.jsp/.., plus any access to /hsqldb, /tmui/Control/jspmap/, /mgmt/tm/util/bash. Enable the corresponding ET Open Snort/Suricata SIDs (ET EXPLOIT F5 TMUI RCE CVE-2020-5902).
      • Endpoint hardening on the BIG-IP: enforce restrictive Self-IP port-lockdown, SSH key-auth only, httpd client-cert authentication, and keep the LocationMatch workaround in place even after patching as defence-in-depth.
      • IAM/least privilege: reduce admin accounts to named individuals, disable shared admin/root, restrict iControl REST to a source-IP allowlist, and enforce MFA on jumphost access to the management plane.
      • Freeze a configuration baseline: diff bigip.conf and bigip_base.conf after patching against a known-good prior version — look for unknown iRules, iApps, monitor scripts, cron entries under /etc/cron.d/, or extra SSH keys in /root/.ssh/authorized_keys.

    3. Runbook step 3

      Detection rules

      • Zeek/Suricata/web-access-log pattern on any reverse proxy or load balancer in front of TMUI: regex /(tmui|hsqldb)/.*(\.\.;|;jsessionid|%3B) — any hit is an exploit attempt or PoC scan.
      • On the BIG-IP itself: process spawn of /bin/bash, /usr/bin/id, curl, wget or nc with parent httpd or java (Tomcat) — via /var/log/audit or an EDR agent if installed. Sigma shape: parent_image endswith httpd AND image in (bash,sh,id,curl,wget).
      • New or modified files under /tmp, /var/tmp, /config written by httpd processes; file-integrity monitoring on /config/bigip.conf, /config/httpd/conf/httpd.conf, /etc/passwd, /root/.ssh/authorized_keys.
      • Outbound connections from BIG-IP management IPs to the internet (DNS, HTTP/S to Pastebin, Github raw, non-allowlisted IPs) — a BIG-IP has no policy-legitimate egress beyond licence and NTP servers.
      • SIEM correlation: failed TMUI logins followed within 60 s by HTTP 200 on /tmui/login.jsp/..;/ or /hsqldb. KQL sketch: WebLogs | where UrlPath matches regex @"(\.\.;|/hsqldb)" | summarize count() by SrcIp, bin(TimeGenerated, 5m).

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: CSA/SingCERT, NVD (NIST), cvelistv5, CISA KEV Catalog

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    —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
    • —
    f5big-ip_access_policy_manager
    • 15.1.0 – < 15.1.0.4
    • 14.1.0 – < 14.1.2.6
    • 15.0.0 – ≤ 15.0.1.4
    • 12.1.0 – < 12.1.5.2
    • 11.6.1 – < 11.6.5.2
    • 13.1.0 – < 13.1.3.4
    • 15.1.0.4
    • 14.1.2.6
    • —
    • 12.1.5.2
    • 11.6.5.2
    • 13.1.3.4
    f5big-ip_advanced_firewall_manager
    • 13.1.0 – < 13.1.3.4
    • 14.1.0 – < 14.1.2.6
    • 12.1.0 – < 12.1.5.2
    • 15.1.0 – < 15.1.0.4
    • 11.6.1 – < 11.6.5.2
    • 15.0.0 – < 15.0.1.4
    • 13.1.3.4
    • 14.1.2.6
    • 12.1.5.2
    • 15.1.0.4
    • 11.6.5.2
    • 15.0.1.4
    f5big-ip_advanced_web_application_firewall
    • 12.1.0 – < 12.1.5.2
    • 15.0.0 – < 15.0.1.4
    • 13.1.0 – < 13.1.3.4
    • 14.1.0 – < 14.1.2.6
    • 11.6.1 – < 11.6.5.2
    • 15.1.0 – < 15.1.0.4
    • 12.1.5.2
    • 15.0.1.4
    • 13.1.3.4
    • 14.1.2.6
    • 11.6.5.2
    • 15.1.0.4
    f5big-ip_analytics
    • 12.1.0 – < 12.1.5.2
    • 11.6.1 – < 11.6.5.2
    • 15.0.0 – < 15.0.1.4
    • 15.1.0 – < 15.1.0.4
    • 13.1.0 – < 13.1.3.4
    • 14.1.0 – < 14.1.2.6
    • 12.1.5.2
    • 11.6.5.2
    • 15.0.1.4
    • 15.1.0.4
    • 13.1.3.4
    • 14.1.2.6
    f5big-ip_application_acceleration_manager
    • 14.1.0 – < 14.1.2.6
    • 15.0.0 – < 15.0.1.4
    • 12.1.0 – < 12.1.5.2
    • 15.1.0 – < 15.1.0.4
    • 13.1.0 – < 13.1.3.4
    • 11.6.1 – < 11.6.5.2
    • 14.1.2.6
    • 15.0.1.4
    • 12.1.5.2
    • 15.1.0.4
    • 13.1.3.4
    • 11.6.5.2
    f5big-ip_application_security_manager
    • 14.1.0 – < 14.1.2.6
    • 15.0.0 – < 15.0.1.4
    • 15.1.0 – < 15.1.0.4
    • 12.1.0 – < 12.1.5.2
    • 11.6.1 – < 11.6.5.2
    • 13.1.0 – < 13.1.3.4
    • 14.1.2.6
    • 15.0.1.4
    • 15.1.0.4
    • 12.1.5.2
    • 11.6.5.2
    • 13.1.3.4
    f5big-ip_ddos_hybrid_defender
    • 15.1.0 – < 15.1.0.4
    • 14.1.0 – < 14.1.2.6
    • 13.1.0 – < 13.1.3.4
    • 12.1.0 – < 12.1.5.2
    • 11.6.1 – < 11.6.5.2
    • 15.0.0 – < 15.0.1.4
    • 15.1.0.4
    • 14.1.2.6
    • 13.1.3.4
    • 12.1.5.2
    • 11.6.5.2
    • 15.0.1.4
    f5big-ip_domain_name_system
    • 11.6.1 – < 11.6.5.2
    • 15.0.0 – < 15.0.1.4
    • 12.1.0 – < 12.1.5.2
    • 13.1.0 – < 13.1.3.4
    • 15.1.0 – < 15.1.0.4
    • 11.6.5.2
    • 15.0.1.4
    • 12.1.5.2
    • 13.1.3.4
    • 15.1.0.4

    Vendors and products

    Weakness classes (CWE)

    • CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

      Base

      The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

      Entry at MITRE CWE-22

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    ANSSI / CERT-FRLicence Ouverte 2.0, as of CERTFR-2020-ALE-015 – Vulnérabilité dans F5 BIG-IP (clôturée 2020-09-15) (opens in a new tab)cert.cyber.gouv.fractively exploited
    Reference tagged as exploitgithub.com (opens in a new tab)PoC (publicly reported)reported, not verified—
    Packet StormBIG IP TMUI Remote Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—
    Packet StormBIG IP TMUI Remote Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—
    Packet StormF5 BIG IP TMUI Directory Traversal File Upload Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—
    Packet StormChecker CVE 2020 5902 (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—
    Packet StormF5 Big IP 13.1.3 Build 0.0.6 Local File Inclusion (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—
    Packet StormF5 BIG IP TMUI Directory Traversal File Upload Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—
    PoC-in-GitHub (nomi-sec)F5-BIG-IP (opens in a new tab)github.comPoC (publicly reported)reported, not verified

    References & sources

    • support.f5.comcsp/article/K52145254Vendor advisory
    • packetstormsecurity.comfiles/158333/BIG-IP-TMUI-Remote-Code-Execution.htmlExploit, Third-party advisory, Vulnerability database
    • packetstormsecurity.comfiles/158334/BIG-IP-TMUI-Remote-Code-Execution.htmlThird-party advisory, Vulnerability database
    • packetstormsecurity.comfiles/158366/F5-BIG-IP-TMUI-Directory-Traversal-File-Upload-Cod…Exploit, Third-party advisory, Vulnerability database
    • kb.cert.orgVU#290915Third-party advisory, Third-party advisory, US government resource
    • criticalstart.comf5-big-ip-remote-code-execution-exploitExploit, Third-party advisory
    • badpackets.netover-3000-f5-big-ip-endpoints-vulnerable-to-cve-2020-5902Exploit, Third-party advisory
    • packetstormsecurity.comfiles/158414/Checker-CVE-2020-5902.htmlThird-party advisory, Vulnerability database
    • github.comCritical-Start/Team-Ares/tree/master/CVE-2020-5902Broken link, Exploit, Third-party advisory
    • packetstormsecurity.comfiles/158581/F5-Big-IP-13.1.3-Build-0.0.6-Local-File-Inclusion.…Exploit, Third-party advisory, Vulnerability database
    • swarm.ptsecurity.comrce-in-f5-big-ipExploit, Third-party advisory
    • packetstormsecurity.comfiles/175671/F5-BIG-IP-TMUI-Directory-Traversal-File-Upload-Cod…Exploit, Third-party advisory, Vulnerability database
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2020-5902government-resource, US government resource
    • cert.cyber.gouv.frANSSI / CERT-FR: CERTFR-2020-ALE-015 – Vulnérabilité dans F5 BIG-IP (clôturée 2020-09-15)cert-fr
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