CVE-2020-28020

Published: May 6, 2021Modified: Jun 17, 2026

9.8

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitability: 3.9 / Impact: 5.9

Source: NVD

Description

Exim 4 before 4.92 allows Integer Overflow to Buffer Overflow, in which an unauthenticated remote attacker can execute arbitrary code by leveraging the mishandling of continuation lines during header-length restriction.

Affected (1)

Products: Exim: Exim

Exim

1 product

Exim

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Exim Exim	From 4.00 to 4.92

Related CWEs

CWE-190

Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

References (6)

http://www.openwall.com/lists/oss-security/2021/07/25/1

Source: cve@mitre.org

Mailing ListThird Party Advisory

http://www.openwall.com/lists/oss-security/2021/08/03/1

Source: cve@mitre.org

Mailing ListThird Party Advisory

https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28020-HSIZE.txt

Source: cve@mitre.org

PatchThird Party Advisory

http://www.openwall.com/lists/oss-security/2021/07/25/1

Source: af854a3a-2127-422b-91ae-364da2661108

Mailing ListThird Party Advisory

http://www.openwall.com/lists/oss-security/2021/08/03/1

Source: af854a3a-2127-422b-91ae-364da2661108

Mailing ListThird Party Advisory

https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28020-HSIZE.txt

Source: af854a3a-2127-422b-91ae-364da2661108

PatchThird Party Advisory

Timeline

No history available yet.