CVE-2020-28024
CRITICALExim 4.00-4.94.1 - Unauthenticated Remote Code Execution via smtp_ungetc Buffer Underwrite
Title source: llmDescription
Exim 4 before 4.94.2 allows Buffer Underwrite that may result in unauthenticated remote attackers executing arbitrary commands, because smtp_ungetc was only intended to push back characters, but can actually push back non-character error codes such as EOF.
References (1)
Core 1
Core References
Third Party Advisory x_refsource_misc
https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28024-UNGET.txt
Scores
CVSS v3
9.8
EPSS
0.0415
EPSS Percentile
89.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Details
CWE
CWE-787
Status
published
Products (1)
exim/exim
4.00 - 4.94.2
Published
May 06, 2021
Tracked Since
Feb 18, 2026