CyberSecBulletin
CVE-2022-22299NVD status: Modified

Fortinet FortiADC, FortiProxy, FortiMail…: Use of Externally-Controlled Format String

CVE-2022-22299 is a high-severity use of externally-controlled format string vulnerability in Fortinet FortiADC, FortiProxy, FortiMail, FortiOS from Fortinet, 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 attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.21% 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 Fortios to 6.4.8 or 7.0.2, whichever matches your release line, or a later version.
  2. Read the advisory on fortiguard.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
FortinetFortinet FortiADC, FortiProxy, FortiMail, FortiOSNot specified in the recordNot stated
FortinetFortiadc6.0.0 through 6.0.4; 6.1.0 through 6.1.6; 6.2.0; 6.2.1Not stated
FortinetFortimail6.4.0 through 6.4.5; 7.0.0 through 7.0.2Not stated
FortinetFortiproxy1.0.0 through 1.0.7; 1.1.0 through 1.1.6; 1.2.0 through 1.2.13; 2.0.0 through 2.0.7; 7.0.0; 7.0.1Not stated
FortinetFortios5.0.0 through 5.0.14; 5.2.0 through 5.2.15; 5.4.0 through 5.4.13; 5.6.0 through 5.6.14; 6.0.0 through 6.0.14; 6.2.0 through 6.2.10; 6.4.0 up to, but not including, 6.4.8; 7.0.0 up to, but not including, 7.0.26.4.8, 7.0.2

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
LowA basic user account is enough.
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighCNA (fortinet.com)
CVSS 3.17.8HighNVD

Official description

A format string vulnerability [CWE-134] in the command line interpreter of FortiADC version 6.0.0 through 6.0.4, FortiADC version 6.1.0 through 6.1.5, FortiADC version 6.2.0 through 6.2.1, FortiProxy version 1.0.0 through 1.0.7, FortiProxy version 1.1.0 through 1.1.6, FortiProxy version 1.2.0 through 1.2.13, FortiProxy version 2.0.0 through 2.0.7, FortiProxy version 7.0.0 through 7.0.1, FortiOS version 6.0.0 through 6.0.14, FortiOS version 6.2.0 through 6.2.10, FortiOS version 6.4.0 through 6.4.8, FortiOS version 7.0.0 through 7.0.2, FortiMail version 6.4.0 through 6.4.5, FortiMail version 7.0.0 through 7.0.2 may allow an authenticated user to execute unauthorized code or commands via specially crafted command arguments.

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

The underlying weakness: Use of Externally-Controlled Format String

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

How developers prevent this class of flaw

  • Choose a language that is not subject to this flaw.
  • Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
  • Run compilers and linkers with high warning levels, since they may detect incorrect usage.

More Use of Externally-Controlled Format String vulnerabilities (CWE-134)

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

Recent Use of Externally-Controlled Format String vulnerabilities

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