Memory leak in OpenSMTPD - CVE-2020-35679
Published: December 24, 2020 / Updated: December 29, 2020
Vulnerability identifier: #VU49180
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-2020-35679
CWE-ID: CWE-401
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform DoS attack on the target system.
The vulnerability exists due memory leak in smtpd/table.c when processing messages. A remote attacker can send a specially crafted message and trigger the daemon to perform multiple regex lookups, which in turn will leak memory.
Affected software
OpenSMTPD
Arch Linux
Gentoo Linux
Fedora
opensmtpd
Arch Linux
Gentoo Linux
Fedora
opensmtpd
How to mitigate CVE-2020-35679
Install updates from vendor's website.
OpenSMTPD - update to 6.8.0p1
opensmtpd - addressed in versions 6.8.0p2-1.el7, 6.8.0p2-1.el8, 6.8.0p2-1.fc32, 6.8.0p2-1.fc33
opensmtpd - addressed in versions 6.8.0p2-1.el7, 6.8.0p2-1.el8, 6.8.0p2-1.fc32, 6.8.0p2-1.fc33