Release of invalid pointer or reference in Exim - CVE-2022-37451
Published: August 22, 2022
Vulnerability identifier: #VU66692
CSH Severity: Medium
CVSS v4: 8.7 [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]
CVE-ID: CVE-2022-37451
CWE-ID: CWE-763
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to an invalid free in pam_converse() function in auths/call_pam.c. A remote attacker can initiate the connection to the affected mail server and perform a denial of service (DoS) attack.
Affected software
Exim
Amazon Linux AMI
Fedora
exim
Amazon Linux AMI
Fedora
exim
How to mitigate CVE-2022-37451
Install updates from vendor's website.
Exim - update to 4.96
exim - update to 4.92-1.37
exim - addressed in versions 4.96-2.fc35, 4.96-2.fc36
exim - update to 4.92-1.37
exim - addressed in versions 4.96-2.fc35, 4.96-2.fc36
External References
- https://www.exim.org/static/doc/security/
- https://github.com/ivd38/exim_invalid_free
- https://github.com/Exim/exim/compare/exim-4.95...exim-4.96
- https://lists.exim.org/lurker/message/20220625.141825.d6de6074.en.html
- https://www.openwall.com/lists/oss-security/2022/08/06/1
- https://github.com/Exim/exim/wiki/EximSecurity
- https://cwe.mitre.org/data/definitions/762.html
- https://github.com/Exim/exim/commit/51be321b27825c01829dffd90f11bfff256f7e42