Improper access control in freeswitch - CVE-2021-41158
Published: October 25, 2021 / Updated: May 15, 2026
Vulnerability identifier: #VU131570
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2021-41158
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: www.freeswitch.org
Affected software:
freeswitch
freeswitch
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper access control in the SIP request handling logic when processing crafted SIP authentication challenges. A remote attacker can send a specially crafted SIP challenge with the realm set to that of a configured gateway to disclose sensitive information.
One demonstrated attack path involves initiating a call to a directory number, which in the default configuration may be reachable through the external SIP profile without authentication.
How to mitigate CVE-2021-41158
Install security update from vendor's website.