CVE-2020-5902F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution Vulnerability
CVE-2020-5902 is a path traversal in F5 BIG-IP, rated critical (9.8 on CVSS 3.1).
Why this priority: Exploited in the wild: listed in CISA's KEV catalog.
Published · Updated · NVD status: Analyzed
What it is
A file name from the request can climb out of the intended folder with sequences like ../, reaching files the service never meant to expose.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything.
What an attacker gains
A successful attack can read the data it protects, change data or behaviour and take it offline. In practice, this kind of flaw lets an attacker read or write files outside the folders the service meant to expose.
Is it being exploited?
CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: it is being exploited in the wild. CISA links it to ransomware campaigns. It can be exploited automatically, at scale. EPSS estimates a 100% chance of exploitation activity in the next 30 days, higher than 100% of scored CVEs.
What to do
- Treat it as urgent: it is on CISA's KEV list. CISA's deadline for US federal agencies: 2022-05-03.
- Apply the update for your edition of F5 BIG-IP. Fixed builds: Big-ip Access Policy Manager: 11.6.5.2, 12.1.5.2, 13.1.3.4; Big-ip Advanced Firewall Manager: 11.6.5.2, 12.1.5.2, 13.1.3.4; Big-ip Advanced Web Application Firewall: 11.6.5.2, 12.1.5.2, 13.1.3.4; Big-ip Analytics: 11.6.5.2, 12.1.5.2, 13.1.3.4; Big-ip Application Acceleration Manager: 11.6.5.2, 12.1.5.2, 13.1.3.4; Big-ip Application Security Manager: 11.6.5.2, 12.1.5.2, 13.1.3.4; and 7 more on this page. Other affected products have their own fixed versions on this page.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
- Check exposed instances for signs of compromise, not only for the version.
Description from NVD
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.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Network edge devices: VPNs, firewalls, routers and gateways. They sit between the internet and internal networks, so a flaw in one is often the first step into everything behind it.
- File storage the service can read or write. The flaw sits between the application and the file system it can reach.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- Between the application and the file system it can reach. An attacker who crosses it can read or write files outside the folders the service meant to expose.
Questions to answer about your own systems
- Where does F5 BIG-IP run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Advisories
Exploits and proofs of concept
- packetstormsecurity.com/files/158333/BIG-IP-TMUI-Remote-Code-Execution.html
- packetstormsecurity.com/files/158366/F5-BIG-IP-TMUI-Directory-Traversal-File-Upload-Code-Execution.html
- packetstormsecurity.com/files/158581/F5-Big-IP-13.1.3-Build-0.0.6-Local-File-Inclusion.html
- packetstormsecurity.com/files/175671/F5-BIG-IP-TMUI-Directory-Traversal-File-Upload-Code-Execution.html
- badpackets.net/over-3000-f5-big-ip-endpoints-vulnerable-to-cve-2020-5902/
- github.com/Critical-Start/Team-Ares/tree/master/CVE-2020-5902
- swarm.ptsecurity.com/rce-in-f5-big-ip/
- www.criticalstart.com/f5-big-ip-remote-code-execution-exploit/
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.