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Fencer Vulns
medium 6.7

CVE-2021-35939 json

It was found that the fix for CVE-2017-7500 and CVE-2017-7501 was incomplete: the check was only implemented for the parent directory of th…

published 2022-08-26 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-22574

cvss
6.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

It was found that the fix for CVE-2017-7500 and CVE-2017-7501 was incomplete: the check was only implemented for the parent directory of the file to be created. A local unprivileged user who owns another ancestor directory could potentially use this flaw to gain root privileges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Patch / fix

  • rpm rpm 4.18
  • rpm Debian 14, Debian 13, Debian 12 4.18.0+dfsg-1

debian advisories DEBIAN-CVE-2021-35939

  • rpm RHEL 8 4.14.3-28.el8_9
  • rpm-cron RHEL 8 4.14.3-28.el8_9
  • rpm-libs RHEL 8 4.14.3-28.el8_9
  • rpm-sign RHEL 8 4.14.3-28.el8_9
  • rpm-build RHEL 8 4.14.3-28.el8_9
  • python3-rpm RHEL 8 4.14.3-28.el8_9
  • rpm-apidocs RHEL 8 4.14.3-28.el8_9
  • rpm-build-libs RHEL 8 4.14.3-28.el8_9

red hat advisories RHSA-2024:0582RHSA-2024:0453RHSA-2024:0424RHSA-2024:0647RHSA-2024:0463RHSA-2024:0435

  • rpm openSUSE Tumbleweed 4.18.0-1.1

opensuse advisories openSUSE-SU-2024:12562-1

  • rpm AlmaLinux 8 4.14.3-28.el8_9
  • rpm-cron AlmaLinux 8 4.14.3-28.el8_9
  • rpm-libs AlmaLinux 8 4.14.3-28.el8_9
  • rpm-sign AlmaLinux 8 4.14.3-28.el8_9
  • rpm-build AlmaLinux 8 4.14.3-28.el8_9
  • python3-rpm AlmaLinux 8 4.14.3-28.el8_9
  • rpm-apidocs AlmaLinux 8 4.14.3-28.el8_9
  • rpm-build-libs AlmaLinux 8 4.14.3-28.el8_9

almalinux advisories ALSA-2024:0647ALSA-2024:0463

  • rpm Rocky Linux 8 4.14.3-28.el8_9

rocky linux advisories RLSA-2024:0647

  • rpm Alpine 3.24, Alpine 3.23, Alpine 3.22 +5 more 4.18.0-r0

alpine advisories ALPINE-CVE-2021-35939

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

  • rpm CBL-Mariner 2.0 4.18.0-1

azure linux advisories AZL-10769

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2021-35939 updated cvss 6.5

rpm: checks for unsafe symlinks are not performed for intermediary directories

  • Red Hat Enterprise Linux 6 rpm, rpm-cron, rpm-libs, rpm-build, rpm-python, rpm-apidocs Red Hat Enterprise Linux 7 rpm, rpm-cron, rpm-libs, rpm-sign, rpm-build, rpm-python, +3 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) rpm-build 4.14.3-28.el8_9, rpm-plugin-fapolicyd 4.14.3-28.el8_9
    fixed: vendor fix RHSA-2024:0647
  • Red Hat Enterprise Linux AppStream (v. 9) rpm-cron 4.16.1.3-27.el9_3, rpm-build 4.16.1.3-27.el9_3, rpm-apidocs 4.16.1.3-27.el9_3, rpm-plugin-ima 4.16.1.3-27.el9_3, rpm-plugin-syslog 4.16.1.3-27.el9_3, rpm-plugin-fapolicyd 4.16.1.3-27.el9_3, +1 more
    fixed: vendor fix RHSA-2024:0463
  • Red Hat Enterprise Linux AppStream EUS (v.8.6) rpm-build 4.14.3-26.el8_6, rpm-plugin-fapolicyd 4.14.3-26.el8_6
    fixed: vendor fix RHSA-2024:0424
  • Red Hat Enterprise Linux AppStream EUS (v.8.8) rpm-build 4.14.3-28.el8_8, rpm-plugin-fapolicyd 4.14.3-28.el8_8
    fixed: vendor fix RHSA-2024:0582
  • Red Hat Enterprise Linux AppStream EUS (v.9.0) rpm-cron 4.16.1.3-14.el9_0.1, rpm-build 4.16.1.3-14.el9_0.1, rpm-apidocs 4.16.1.3-14.el9_0.1, rpm-plugin-ima 4.16.1.3-14.el9_0.1, rpm-plugin-syslog 4.16.1.3-14.el9_0.1, rpm-plugin-fapolicyd 4.16.1.3-14.el9_0.1, +1 more
    fixed: vendor fix RHSA-2024:0435
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) rpm-cron 4.16.1.3-24.el9_2, rpm-build 4.16.1.3-24.el9_2, rpm-apidocs 4.16.1.3-24.el9_2, rpm-plugin-ima 4.16.1.3-24.el9_2, rpm-plugin-syslog 4.16.1.3-24.el9_2, rpm-plugin-fapolicyd 4.16.1.3-24.el9_2, +1 more
    fixed: vendor fix RHSA-2024:0453
  • Red Hat Enterprise Linux BaseOS (v. 8) rpm 4.14.3-28.el8_9, rpm-cron 4.14.3-28.el8_9, rpm-libs 4.14.3-28.el8_9, rpm-sign 4.14.3-28.el8_9, python3-rpm 4.14.3-28.el8_9, rpm-apidocs 4.14.3-28.el8_9, +6 more
    fixed: vendor fix RHSA-2024:0647
show 7 more
  • Red Hat Enterprise Linux BaseOS (v. 9) rpm 4.16.1.3-27.el9_3, rpm-libs 4.16.1.3-27.el9_3, rpm-sign 4.16.1.3-27.el9_3, python3-rpm 4.16.1.3-27.el9_3, rpm-sign-libs 4.16.1.3-27.el9_3, rpm-build-libs 4.16.1.3-27.el9_3, +2 more
    fixed: vendor fix RHSA-2024:0463
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) rpm 4.14.3-26.el8_6, rpm-cron 4.14.3-26.el8_6, rpm-libs 4.14.3-26.el8_6, rpm-sign 4.14.3-26.el8_6, python3-rpm 4.14.3-26.el8_6, rpm-apidocs 4.14.3-26.el8_6, +6 more
    fixed: vendor fix RHSA-2024:0424
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) rpm 4.14.3-28.el8_8, rpm-cron 4.14.3-28.el8_8, rpm-libs 4.14.3-28.el8_8, rpm-sign 4.14.3-28.el8_8, python3-rpm 4.14.3-28.el8_8, rpm-apidocs 4.14.3-28.el8_8, +6 more
    fixed: vendor fix RHSA-2024:0582
  • Red Hat Enterprise Linux BaseOS EUS (v.9.0) rpm 4.16.1.3-14.el9_0.1, rpm-libs 4.16.1.3-14.el9_0.1, rpm-sign 4.16.1.3-14.el9_0.1, python3-rpm 4.16.1.3-14.el9_0.1, rpm-sign-libs 4.16.1.3-14.el9_0.1, rpm-build-libs 4.16.1.3-14.el9_0.1, +2 more
    fixed: vendor fix RHSA-2024:0435
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) rpm 4.16.1.3-24.el9_2, rpm-libs 4.16.1.3-24.el9_2, rpm-sign 4.16.1.3-24.el9_2, python3-rpm 4.16.1.3-24.el9_2, rpm-sign-libs 4.16.1.3-24.el9_2, rpm-build-libs 4.16.1.3-24.el9_2, +2 more
    fixed: vendor fix RHSA-2024:0453
  • Red Hat OpenShift Container Platform 4.13 openshift4-wincw/windows-machine-config-rhel9-operator 8.1.2-13, openshift4-wincw/windows-machine-config-operator-bundle v8.1.2-13
    fixed: vendor fix RHSA-2024:1477
  • Red Hat RHODF 4.15 for RHEL 9 odf4/cephcsi-rhel9 v4.15.0-37, odf4/odf-cli-rhel9 v4.15.0-22, odf4/mcg-core-rhel9 v4.15.0-68, odf4/odf-console-rhel9 v4.15.0-57, odf4/mcg-rhel9-operator v4.15.0-39, odf4/ocs-rhel9-operator v4.15.0-79, +20 more
    fixed: vendor fix RHSA-2024:1383

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

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1964129 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.7 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected products

  • n/a RPM

Classification

Weakness
  • CWE-59 Improper Link Resolution Before File Access

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.