CVE-2020-8794 Memory corruption in n/a

What is CVE-2020-8794?

CVE-2020-8794 is a critical memory corruption vulnerability in Canonical Ubuntu Linux, published on 25 Feb 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

OpenSMTPD before 6.6.4 allows remote code execution because of an out-of-bounds read in mta_io in mta_session.c for multi-line replies. Although this vulnerability affects the client side of OpenSMTPD, it is possible to attack a server because the server code launches the client code during bounce handling.

Weakness: CWE-125

Which versions are affected by CVE-2020-8794?

It affects 4 products.

Products include Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Opensmtpd Opensmtpd.

How do I fix CVE-2020-8794?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2020-8794 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-8794 exists.

Public exploit code: 1 Metasploit module and 2 Exploit-DB entries.

Other vulnerabilities in Canonical Ubuntu Linux

• CVE-2020-11651 SaltStack Salt Authentication Bypass Exploited Critical 9.8
• CVE-2020-7247 OpenSMTPD Remote Code Execution Exploited Critical 9.8
• CVE-2019-16928 Exim Out-of-bounds Write Exploited Critical 9.8
• CVE-2018-6789 Exim Buffer Overflow Exploited Critical 9.8
• CVE-2015-2590 Oracle Java SE and Java SE Embedded Remote Code Execution Exploited Critical 9.8

All Canonical Ubuntu Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-8794, DSA-4634-1, GHSA-hmw3-c3g9-px9f, UBUNTU-CVE-2020-8794.