Improperly implemented security check for standard in firefox-esr (Alpine package)

Published: 2021-02-26
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-23968
Exploitation vector Network
Public exploit N/A
Vulnerable software
firefox-esr (Alpine package)
Operating systems & Components / Operating system package or component

Vendor Alpine Linux Development Team

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Improperly implemented security check for standard

EUVDB-ID: #VU50881

Risk: Medium


CVE-ID: CVE-2021-23968

CWE-ID: CWE-358 - Improperly Implemented Security Check for Standard

Exploit availability: No


The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to incorrect implementation of W3C Content Security Policy. If Content Security Policy blocked frame navigation, the full destination of a redirect served in the frame was reported in the violation report; as opposed to the original frame URI. A remote attacker can gain knowledge of sensitive information contained in such URIs.


Install update from vendor's website.

Vulnerable software versions

firefox-esr (Alpine package): 60.4.0-r0 - 78.7.1-r0

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?