CyberSecBulletin
CVE-2024-55594NVD status: Analyzed

FortiWeb: Improper Handling of Syntactically Invalid Structure

CVE-2024-55594 is a critical-severity improper handling of syntactically invalid structure vulnerability in FortiWeb from Fortinet, 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. Affected FortiWeb versions: 7.4.0 through 7.4.6; 7.2.0 through 7.2.10; 7.0.0 through 7.0.10. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of FortiWeb you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on fortiguard.fortinet.com for workarounds and exact fixed builds.
  3. 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
FortinetFortiWeb7.4.0 through 7.4.6; 7.2.0 through 7.2.10; 7.0.0 through 7.0.10Not stated

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 3.15.6MediumCNA (fortinet.com)
CVSS 3.19.8CriticalNVD

Official description

An improper handling of syntactically invalid structure in Fortinet FortiWeb at least vesrions 7.4.0 through 7.4.6 and 7.2.0 through 7.2.10 and 7.0.0 through 7.0.10 allows attacker to execute unauthorized code or commands via HTTP/S crafted requests.

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

The underlying weakness: Improper Handling of Syntactically Invalid Structure

The product does not handle or incorrectly handles input that is not syntactically well-formed with respect to the associated specification.

More Improper Handling of Syntactically Invalid Structure vulnerabilities (CWE-228)

Timeline

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

References

Other vulnerabilities in FortiWeb

All FortiWeb vulnerabilities

Recent Improper Handling of Syntactically Invalid Structure vulnerabilities

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