#VU21399 Heap-based buffer overflow in Exim - CVE-2019-16928
Published: September 28, 2019 / Updated: March 8, 2022
Vulnerability identifier: #VU21399
Vulnerability risk: High
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Amber
CVE-ID: CVE-2019-16928
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerable software:
Exim
Exim
Software vendor:
Exim
Exim
Description
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the string_vformat() function in string.c when processing an overly long argument for EHLO command. A remote non-authenticated attacker can send a very long string as an argument for the EHLO command, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Remediation
Install the latest version from vendor's website.
External links
- http://www.openwall.com/lists/oss-security/2019/09/28/1
- http://www.openwall.com/lists/oss-security/2019/09/28/2
- http://www.openwall.com/lists/oss-security/2019/09/28/3
- https://bugs.exim.org/show_bug.cgi?id=2449
- https://git.exim.org/exim.git/commit/478effbfd9c3cc5a627fc671d4bf94d13670d65f
- https://lists.exim.org/lurker/message/20190927.032457.c1044d4c.en.html