CyberSecBulletin
CVE-2023-22657NVD status: Modified

F5OS-A: Improper Neutralization of Special Elements used in a Command

CVE-2023-22657 is a high-severity improper neutralization of special elements used in a command vulnerability in F5OS-A from F5, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 1.3.0 as the first without the flaw, so updating F5OS-A to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.46% 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 F5OS-A to 1.3.0 or a later version.
  2. Update F5OS-C to 1.5.0 or a later version.
  3. Read the advisory on my.f5.com for workarounds and exact fixed builds.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
F5F5OS-A1.2.0 up to, but not including, 1.3.01.3.0
F5F5OS-C1.3.0 up to, but not including, 1.5.01.5.0

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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.0HighCNA (f5.com)
CVSS 3.17.8HighNVD

Official description

On F5OS-A beginning in version 1.2.0 to before 1.3.0 and F5OS-C beginning in version 1.3.0 to before 1.5.0, processing F5OS tenant file names may allow for command injection. 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: Improper Neutralization of Special Elements used in a Command

The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.

How developers prevent this class of flaw

  • If at all possible, use library calls rather than external processes to recreate the desired functionality.
  • If possible, ensure that all external commands called from the program are statically created.
  • Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.

More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in F5OS-A

All F5OS-A vulnerabilities

Recent Improper Neutralization of Special Elements used in a Command vulnerabilities

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