HOMEVULNERABILITIESCVE-2021-21696
CRITICAL

CVE-2021-21696

NVD-CWE-OtherPublished: November 4, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not limit agent read/write access to the libs/ directory inside build directories when using the FilePath APIs, allowing attackers in control of agent processes to replace the code of a trusted library with a modified variant. This results in unsandboxed code execution in the Jenkins controller process.

NVD Source

Technical Analysis

CVE-2021-21696 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

jenkins1 product(s)
jenkins
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttp://www.openwall.com/lists/oss-security/2021/11/04/3
ADVISORYhttps://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423
ADVISORYhttp://www.openwall.com/lists/oss-security/2021/11/04/3
ADVISORYhttps://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423

All References (4)

→
http://www.openwall.com/lists/oss-security/2021/11/04/3Mailing List · Third Party Advisory
→
https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423Mitigation · Vendor Advisory
→
http://www.openwall.com/lists/oss-security/2021/11/04/3Mailing List · Third Party Advisory
→
https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423Mitigation · Vendor Advisory

Quick Facts

CVE IDCVE-2021-21696
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessNVD-CWE-Other
CISA KEVNo
Affected1 vendor(s)
PublishedNov 4, 2021

Related CVEs (NVD-CWE-Other)

CVE-2006-6861
10.0
CVE-1999-0789
10.0
CVE-1999-0192
10.0
CVE-2004-0246
10.0
CVE-2000-0584
10.0
CVE-2000-0389
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-21696 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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