Stored cross-site scripting in Gitlab Community Edition and GitLab Enterprise Edition - CVE-2021-39887
Published: October 4, 2021
Vulnerability identifier: #VU57012
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2021-39887
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in the GitLab Flavored Markdown. A remote authenticated attacker can inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
Affected software
Gitlab Community Edition
GitLab Enterprise Edition
GitLab Enterprise Edition
How to mitigate CVE-2021-39887
Install updates from vendor's website.
Gitlab Community Edition - addressed in versions 14.1.7, 14.2.5, 14.3.1
GitLab Enterprise Edition - addressed in versions 14.1.7, 14.2.5, 14.3.1
GitLab Enterprise Edition - addressed in versions 14.1.7, 14.2.5, 14.3.1