CVE-2024-23903Network attack vector

Webhook token recovery via nonconstant-time comparison

Published Jan 24, 2024 · Updated Feb 13, 2025

Timing side channel in Jenkins GitLab Branch Source Plugin 684.vea_fa_7c1e2fe3 and earlier allows remote attackers to recover webhook tokens. The isValidToken methods in GitLabWebHookAction and GitLabSystemHookAction compare attacker-supplied tokens with stored secrets using Objects.equals, leaking response timing. Network access to a configured webhook endpoint and repeated measurements are required; a recovered token permits forged webhook requests.

CVSS severity5.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Timing side channel in Jenkins GitLab Branch Source Plugin 684.vea_fa_7c1e2fe3 and earlier allows remote attackers to recover webhook tokens. The isValidToken methods in GitLabWebHookAction and GitLabSystemHookAction compare attacker-supplied tokens with stored secrets using Objects.equals, leaking response timing. Network access to a configured webhook endpoint and repeated measurements are required; a recovered token permits forged webhook requests.

The record

CVE
CVE-2024-23903
Published
Jan 24, 2024
Updated
Feb 13, 2025
Vendor
Jenkins Project
Product
GitLab Branch Source
Classifications
CWE-697
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 24, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0 <=684.vea_fa_7c1e2fe3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Jenkins Project · GitLab Branch Sourceversion=0 <=684.vea_fa_7c1e2fe3

Published CVSS scores

5.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-697Incorrect Comparison

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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