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Fencer Vulns
high 8.8

CVE-2020-28021 json

Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters.

published 2021-05-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-20512

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.1%
EPSS 4.1% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters. An authenticated remote SMTP client can insert newline characters into a spool file (which indirectly leads to remote code execution as root) via AUTH= in a MAIL FROM command.

Patch / fix

  • exim exim 4.94.2
  • exim4 Debian 14, Debian 13, Debian 12 4.94.2-1

debian advisories DEBIAN-CVE-2020-28021

  • exim4 Ubuntu 18.04 LTS 4.90.1-1ubuntu1.8
  • exim4 Ubuntu 20.04 LTS 4.93-13ubuntu1.5
  • exim4 Ubuntu Pro 14.04 LTS 4.82-3ubuntu2.4+esm3
  • exim4 Ubuntu Pro 16.04 LTS 4.86.2-2ubuntu2.6+esm1

ubuntu advisories UBUNTU-CVE-2020-28021

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • exim openSUSE Tumbleweed 4.94.2-4.2
  • exim Package Hub 15 SP2 4.94.2-bp152.6.4.1
  • libspf2 Package Hub 15 SP2 1.2.10-bp152.5.1
  • exim Package Hub 15 SP1 4.94.2-bp151.2.4.1
  • libspf2 Package Hub 15 SP1 1.2.10-bp151.4.1
  • exim openSUSE Leap 15.2 4.94.2-lp152.8.3.1

opensuse advisories openSUSE-SU-2024:10746-1openSUSE-SU-2021:0754-1openSUSE-SU-2021:0753-1openSUSE-SU-2021:0677-1

  • exim Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 4.94.2-r0

alpine advisories ALPINE-CVE-2020-28021

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • exim Arch Linux 4.94.2-1

arch linux advisories AVG-1911

Exploit prediction

4.14% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 9.0 AV:N/AC:L/Au:S/C:C/I:C/A:C

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.