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Fencer Vulns
medium 6.3

CVE-2021-27216 json

Exim 4 before 4.94.2 has Execution with Unnecessary Privileges.

published 2021-05-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-13981

cvss
6.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 62%
public exploits
0
none known

Summary

Exim 4 before 4.94.2 has Execution with Unnecessary Privileges. By leveraging a delete_pid_file race condition, a local user can delete arbitrary files as root. This involves the -oP and -oPX options.

Patch / fix

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

debian advisories DEBIAN-CVE-2021-27216

  • 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-2021-27216

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

alpine advisories ALPINE-CVE-2021-27216

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

Exploit prediction

0.98% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • exim.org https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28007-LFDIR.txt referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
NVD 2.0 6.3 AV:L/AC:M/Au:N/C:N/I:C/A:C

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

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.