CVE-2020-28024

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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
9.8 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
mitreCNA
---
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CVEADP
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Base Score
CVSS 3.x
EPSS Score
Percentile: 78%
VendorProductVersion
eximexim
4.00 ≤
𝑥
< 4.94.2
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
exim4
bullseye
4.94.2-7+deb11u3
fixed
bullseye (security)
4.94.2-7+deb11u4
fixed
bookworm
4.96-15+deb12u5
fixed
bookworm (security)
4.96-15+deb12u5
fixed
sid
4.98-2
fixed
trixie
4.98-2
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
exim4
jammy
Fixed 4.94-15ubuntu1.2
released
impish
Fixed 4.94-15ubuntu1.2
released
hirsute
Fixed 4.94-15ubuntu1.2
released
groovy
Fixed 4.94-7ubuntu1.2
released
focal
Fixed 4.93-13ubuntu1.5
released
bionic
Fixed 4.90.1-1ubuntu1.8
released
xenial
Fixed 4.86.2-2ubuntu2.6+esm1
released
trusty
Fixed 4.82-3ubuntu2.4+esm3
released
Common Weakness Enumeration
References
https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28024-UNGET.txt
https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28024-UNGET.txt