Time-of-check Time-of-use (TOCTOU) Race Condition in jenkins (Alpine package)

1) Time-of-check Time-of-use (TOCTOU) Race Condition

EUVDB-ID: #VU50020

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-2021-21615

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

Exploit availability: No

Description

The vulnerability allows a remote user to gain access to sensitive information.

The vulnerability exists due to a race condition in the file browser for workspaces. A remote user with Job/Workspace permission and the ability to control workspace contents, e.g., with Job/Configure permission or the ability to change SCM contents, can create symbolic links that allow them to access files outside workspaces using the workspace browser.

Note, the vulnerability is caused by incorrect patch for #VU49527

Mitigation

Install update from vendor's website.

Vulnerable software versions

jenkins (Alpine package): 2.73.3-r0 - 2.275-r0

External links

http://git.alpinelinux.org/aports/commit/?id=668a0b69fd6ea611c8db5801789e2be9d4bb309a

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.