CyberSecBulletin
CVE-2023-3900NVD status: Modified

GitLab: Improper Validation of Specified Type of Input

CVE-2023-3900 is a high-severity improper validation of specified type of input vulnerability in GitLab, 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 16.1.3, 16.2.2 as the first without the flaw, so updating GitLab to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.92% chance of exploitation within 30 days, higher than 61% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update GitLab to 16.1.3 or 16.2.2, whichever matches your release line, or a later version.
  2. 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
GitLabGitLab16.1 up to, but not including, 16.1.3; 16.2 up to, but not including, 16.2.216.1.3, 16.2.2

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
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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.14.3MediumCNA (gitlab.com)
CVSS 3.17.5HighNVD

Official description

An issue has been discovered in GitLab CE/EE affecting all versions starting from 16.1 before 16.1.3, all versions starting from 16.2 before 16.2.2. An invalid 'start_sha' value on merge requests page may lead to Denial of Service as Changes tab would not load.

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

The underlying weakness: Improper Validation of Specified Type of Input

The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type.

More Improper Validation of Specified Type of Input vulnerabilities (CWE-1287)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other references

Other vulnerabilities in GitLab

All GitLab vulnerabilities

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