Vulnerability identifier: #VU24761

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-2102

CWE-ID: CWE-310

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Jenkins
Server applications / Application servers
Jenkins LTS
Server applications / Application servers

Vendor: Jenkins

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to the affected software does not use a constant-time comparison when checking whether two HMACs are equal. A remote authenticated attacker can use statistical methods to obtain a valid HMAC for an attacker-controlled input value.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Jenkins: 2.0 - 2.218

Jenkins LTS: 2.7.1 - 2.204.1

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External links
http://www.openwall.com/lists/oss-security/2020/01/29/1
http://jenkins.io/security/advisory/2020-01-29/#SECURITY-1660

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.