CyberSecBulletin
CVE-2020-5902Exploited in the wildNVD status: Analyzed

F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution

Published Updated By the CyberSecBulletin desk

CVE-2020-5902 is a critical-severity improper limitation of a pathname to a restricted directory vulnerability in BIG-IP, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. CISA added it to the Known Exploited Vulnerabilities catalogue on November 3, 2021, which means attacks have been observed in the wild, including in ransomware campaigns.

Patch now

Attackers are already exploiting this vulnerability, according to CISA.

What to do

  1. Update Big-ip Access Policy Manager to 11.6.5.2 or 12.1.5.2 or 13.1.3.4 or 14.1.2.6, whichever matches your release line, or a later version.
  2. Update Big-ip Advanced Firewall Manager to 11.6.5.2 or 12.1.5.2 or 13.1.3.4 or 14.1.2.6, whichever matches your release line, or a later version.
  3. Update Big-ip Advanced Web Application Firewall to 11.6.5.2 or 12.1.5.2 or 13.1.3.4 or 14.1.2.6, whichever matches your release line, or a later version.
  4. CISA's required action: Apply updates per vendor instructions.
  5. Read the advisory on support.f5.com for workarounds and exact fixed builds.
  6. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
BIG-IPBIG-IPNot specified in the recordNot stated
F5Big-ip Access Policy Manager11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 through 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.1.0.4
F5Big-ip Advanced Firewall Manager11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Advanced Web Application Firewall11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Analytics11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Application Acceleration Manager11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Application Security Manager11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Ddos Hybrid Defender11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Domain Name System11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Fraud Protection Service11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Global Traffic Manager11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Link Controller11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Local Traffic Manager11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5Big-ip Policy Enforcement Manager11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4
F5SSL Orchestrator11.6.1 up to, but not including, 11.6.5.2; 12.1.0 up to, but not including, 12.1.5.2; 13.1.0 up to, but not including, 13.1.3.4; 14.1.0 up to, but not including, 14.1.2.6; 15.0.0 up to, but not including, 15.0.1.4; 15.1.0 up to, but not including, 15.1.0.411.6.5.2, 12.1.5.2, 13.1.3.4, 14.1.2.6, 15.0.1.4, 15.1.0.4

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.19.8CriticalCISA (ADP)
CVSS 2.010.0HighNVD

Official 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: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory

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.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
  • Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.

More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)

Timeline

  1. CVE record published.
  2. Added to CISA's Known Exploited Vulnerabilities catalogue.
  3. Deadline for US federal agencies to remediate, set by CISA.
  4. CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
  5. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Technical write-ups (may include proof of concept)

Other vulnerabilities in BIG-IP

All BIG-IP vulnerabilities

Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities

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