PT-2022-3997 · Exim+1 · Exim+1

Evgeny Legerov · Published 2022-08-06 · Updated 2023-08-25 · CVE-2022-37451

Positive Technologies (AI Summary)

CVSS v2.0

10

High

Base vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions Exim versions prior to 4.96

Description The issue is related to the use of memory after it has been freed in the pam converse function of the Exim mail server. This can be exploited by a remote attacker to impact the confidentiality, integrity, and availability of protected information. The problem arises from an invalid free in pam converse in auths/call pam.c due to the lack of use of store free after store malloc.

Recommendations For versions prior to 4.96, update to version 4.96 or later to resolve the issue. As a temporary workaround, consider restricting access to the pam converse function in auths/call pam.c to minimize the risk of exploitation.

Exploit

Fix

Use After Free

Weakness Enumeration

CWE-763

CWE-416

Related Identifiers

ALT-PU-2023-4105

ALT-PU-2023-4919

ALT-PU-2023-4920

ALT-PU-2023-5120

BDU:2022-04830

CVE-2022-37451

Affected Products

Alt Linux

Exim

References · 22

• 🔥❌ https://github.com/ivd38/exim_invalid_free · Exploit, Deleted
• https://github.com/Exim/exim/commit/51be321b27825c01829dffd90f11bfff256f7e42 · Patch
• https://exim.org/static/doc/security · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2022-37451 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2022-37451 · Security Note
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LETR5CVDPFOFQHXCJP6NFLG52JZHQYDY · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2022-37451 · Vendor Advisory
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XSWDF4QEXD4TDWQLYQOWCHBJKTDQR4Z7 · Vendor Advisory
• https://lists.exim.org/lurker/message/20220625.141825.d6de6074.en.html · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2022-37451 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2022-37451 · Vendor Advisory
• https://ubuntu.com/security/CVE-2022-37451 · Vendor Advisory
• https://bdu.fstec.ru/vul/2022-04830 · Security Note
• https://cve.org/CVERecord?id=CVE-2022-37451 · Security Note
• https://github.com/Exim/exim/wiki/EximSecurity · Note