CVE-2021-35939

Exp

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.

Published: 2022-08-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-35939 is rated Exploit Available (54.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.15%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-35939

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-35939

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-18 0.15% 0.15% +0.00%
2 2025-12-07 0.15% 0.15% -0.00%
3 2025-11-21 — 0.15% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-35939

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.8 5.9 [email protected]

Weakness enumeration for CVE-2021-35939

OS Trackers for CVE-2021-35939

vendor priority summary link
alpine high CVE-2021-35939: 1 source package rows (rpm); 14 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 7. https://security.alpinelinux.org/vuln/CVE-2021-35939
debian not yet assigned CVE-2021-35939 not yet assigned priority: Debian including 1 source packages (rpm), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-35939
gentoo high CVE-2021-35939: 1 GLSA(s) (202210-22), 1 atom(s) (app-arch/rpm); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-35939
redhat medium — https://access.redhat.com/security/cve/CVE-2021-35939
suse medium CVE-2021-35939 severity moderate: SUSE including 53 source package names (librpmbuild10-4.20.1-160000.2.2, librpmbuild9-4.18.0-1.1, …), 118 product×package rows across 38 product lines (SUSE Enterprise Storage 7, SUSE Liberty Linux 8, … (38 product lines)): Will Not Fix 73, Fixed 45. https://www.suse.com/security/cve/CVE-2021-35939/
ubuntu medium CVE-2021-35939 medium priority: Ubuntu including 1 source packages (rpm), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needs-triage 8. https://ubuntu.com/security/CVE-2021-35939

Affected software / configurations for CVE-2021-35939

Vendor Product Version Raw CPE
rpm rpm < 4.18 cpe:2.3:a:rpm:rpm:*:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*

References for CVE-2021-35939

cvelogic Threat Intelligence