SB2021072607 - Multiple vulnerabilities in Asterisk

Description

This security bulletin contains information about 2 vulnerabilities.

1) Resource management error (CVE-ID: CVE-2021-31878)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources within the application in PJSIP channel driver in res_pjsip_session.c. A remote user can send a re-INVITE message without SDP after Asterisk has sent a BYE request and perform a denial of service (DoS) attack.

2) Input validation error (CVE-ID: CVE-2021-32558)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input within the IAX2 channel driver chan_iax2.c. A remote attacker can send a packet that contains an unsupported media format and perform a denial of service (DoS) attack.

Remediation

Install update from vendor's website.

References

• https://downloads.asterisk.org/pub/security/AST-2021-007.html
• https://downloads.asterisk.org/pub/security/AST-2021-008.html