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Fencer Intel
low 2.5

CVE-2021-23239 json

The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning…

published 5y ago modified 4mo ago also EUVD-2021-10338

cvss
2.5
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 63%
public exploits
0
none known

Summary

The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning a sudo_edit.c race condition in replacing a user-controlled directory by a symlink to an arbitrary path.

Patch / fix

  • sudo_project sudo 1.8.32, 1.9.5
  • sudo Debian 14, Debian 13, Debian 12 1.9.5-1

debian advisories DEBIAN-CVE-2021-23239

  • sudo Ubuntu 16.04 LTS 1.8.16-0ubuntu1.10
  • sudo Ubuntu 18.04 LTS 1.8.21p2-3ubuntu1.4
  • sudo Ubuntu 20.04 LTS 1.8.31-1ubuntu1.2

ubuntu advisories UBUNTU-CVE-2021-23239

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

  • sudo RHEL 8 1.8.29-7.el8

red hat advisories RHSA-2021:1723

  • sudo SLES for SAP 12 SP2, SLES 12 SP2-LTSS, SLES 12 SP2-BCL +1 more 1.8.10p3-10.29.1
  • sudo SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +12 more 1.8.22-4.15.1
  • sudo SLES for SAP 12 SP4, SLES for SAP 12 SP3, SLES 12 SP4-LTSS +8 more 1.8.20p2-3.20.1
  • sudo SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 1.8.27-4.6.1

suse advisories SUSE-SU-2021:0232-1SUSE-SU-2021:0227-1SUSE-SU-2021:0226-1SUSE-SU-2021:0225-1

  • sudo openSUSE Tumbleweed 1.9.7p2-1.4
  • sudo openSUSE Leap 15.2 1.8.22-lp152.8.6.1
  • sudo openSUSE Leap 15.1 1.8.22-lp151.5.12.1

opensuse advisories openSUSE-SU-2024:11413-1openSUSE-SU-2021:0170-1openSUSE-SU-2021:0169-1

  • sudo Rocky Linux 8 1.8.29-7.el8

rocky linux advisories RLSA-2021:1723

  • sudo Alpine 3.11, Alpine 3.10 1.9.5p2-r0
  • sudo Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 1.9.5-r0

alpine advisories ALPINE-CVE-2021-23239

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

  • sudo Arch Linux 1.9.5.p2-1

arch linux advisories AVG-1431

Is CVE-2021-23239 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-23239 updated cvss 2.5

sudo: possible directory existence test due to race condition in sudoedit

  • Red Hat Enterprise Linux 5 sudo Red Hat Enterprise Linux 6 sudo Red Hat Enterprise Linux 7 sudo
    affected: workaround, no fix planned “Enabling the symbolic link protection (/proc/sys/fs/protected_symlinks set to 1) is sufficient to mitigate this flaw.”
  • Red Hat Enterprise Linux BaseOS (v. 8) sudo 1.8.29-7.el8
    fixed: vendor fix “Enabling the symbolic link protection (/proc/sys/fs/protected_symlinks set to 1) is sufficient to mitigate this flaw.” RHSA-2021:1723
  • Red Hat Enterprise Linux 9 sudo, sudo-python-plugin
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.00% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • bugzilla.suse.com https://bugzilla.suse.com/show_bug.cgi?id=CVE-2021-23239 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 2.5 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 1.9 AV:L/AC:M/Au:N/C:P/I:N/A:N

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

References

Sources

Fencer Intel 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.