CyberSecBulletin
CVE-2025-61951NVD status: Analyzed

BIG-IP: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2025-61951 is a high-severity out-of-bounds read vulnerability in BIG-IP from F5, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 17.5.1, 17.1.3, 16.1.6.1 as the first without the flaw, so updating BIG-IP to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update BIG-IP to 17.5.1 or 17.1.3 or 16.1.6.1, whichever matches your release line, or a later version.
  2. Update Big-ip Access Policy Manager to 16.1.6.1 or 17.1.3, whichever matches your release line, or a later version.
  3. Update Big-ip Advanced Firewall Manager to 16.1.6.1 or 17.1.3, whichever matches your release line, or a later version.
  4. Read the advisory on my.f5.com for workarounds and exact fixed builds.
  5. 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
F5BIG-IP17.5.0 up to, but not including, 17.5.1; 17.1.0 up to, but not including, 17.1.3; 16.1.0 up to, but not including, 16.1.6.117.5.1, 17.1.3, 16.1.6.1
F5Big-ip Access Policy Manager16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Advanced Firewall Manager16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Advanced Web Application Firewall16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Analytics16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Application Acceleration Manager16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Application Security Manager16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Application Visibility And Reporting16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Automation Toolchain16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Carrier-grade Nat16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Container Ingress Services16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Ddos Hybrid Defender16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Domain Name System16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Edge Gateway16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Fraud Protection Service16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Global Traffic Manager16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Link Controller16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Local Traffic Manager16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Policy Enforcement Manager16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip SSL Orchestrator16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Webaccelerator16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3
F5Big-ip Websafe16.1.0 up to, but not including, 16.1.6.1; 17.1.0 up to, but not including, 17.1.3; 17.5.016.1.6.1, 17.1.3

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
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (f5.com).

Scoring systemScoreSeverityScored by
CVSS 4.08.7HighCNA (f5.com)
CVSS 3.17.5HighCNA (f5.com)

Official description

Undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. This issue may occur when a Datagram Transport Layer Security (DTLS) 1.2 virtual server is enabled with a Server SSL profile that is configured with a certificate, key, and the SSL Sign Hash set to ANY, and the backend server is enabled with DTLS 1.2 and client authentication. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

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

The underlying weakness: Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that provides appropriate memory abstractions.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in BIG-IP

All BIG-IP vulnerabilities

Recent Out-of-bounds Read vulnerabilities

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