CVE-2021-33938

Exp

Buffer overflow vulnerability in function prune_to_recommended in src/policy.c in libsolv before 0.7.17 allows attackers to cause a Denial of Service.

Published: 2021-09-02 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-33938 is rated Exploit Available (51.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.06%). 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-2021-33938

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

Exploit prediction scoring system (EPSS) score for CVE-2021-33938

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 2025-11-21 0.32% 0.06% -0.26%
2 2025-11-18 0.05% 0.32% +0.27%
3 2025-06-06 — 0.05% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-33938

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-33938

OS Trackers for CVE-2021-33938

vendor priority summary link
debian not yet assigned CVE-2021-33938 not yet assigned priority: Debian including 1 source packages (libsolv), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-33938
redhat medium — https://access.redhat.com/security/cve/CVE-2021-33938
suse — CVE-2021-33938 severity not set: SUSE including 12 source package names (libsolv, libsolv-0.7.16-3.el8_4, …), 131 product×package rows across 36 product lines (SUSE CaaS Platform 4.0, SUSE CaaS Platform 4.5, … (36 product lines)): Known Not Affected 127, Fixed 4. https://www.suse.com/security/cve/CVE-2021-33938/
ubuntu medium CVE-2021-33938 medium priority: Ubuntu including 1 source packages (libsolv), 15 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 10, needed 2, DNE 1, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2021-33938

Affected software / configurations for CVE-2021-33938

Vendor Product Version Raw CPE
opensuse libsolv <= 0.7.17 cpe:2.3:a:opensuse:libsolv:*:*:*:*:*:*:*:*

References for CVE-2021-33938

URL Tags
https://github.com/openSUSE/libsolv/issues/420 Exploit Issue Tracking Third Party Advisory
cvelogic Threat Intelligence