Skip to content
Noroxi
CVE-2021-33938· NVD / CVE Program· CNA mitre

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

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.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Sep 2, 2021
Updated
Jun 16, 2026
EPSS
1.4% · 72th percentile
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.4%

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Affected systems

VendorProduct
opensuselibsolv

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • opensuse libsolvup to 0.7.17 inclusive

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8libsolv-develbefore 0.7.16-3.el8_40.7.16-3.el8_4
AlmaLinux:8libsolv-toolsbefore 0.7.16-3.el8_40.7.16-3.el8_4
Debian:12libsolvbefore 0.7.17-10.7.17-1
Red Hat:enterprise_linux:8::baseoslibsolvbefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseoslibsolv-debuginfobefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseoslibsolv-debugsourcebefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseoslibsolv-demo-debuginfobefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseoslibsolv-tools-debuginfobefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseosperl-solv-debuginfobefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseospython3-solvbefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseospython3-solv-debuginfobefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::baseosruby-solv-debuginfobefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::crblibsolv-develbefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:enterprise_linux:8::crblibsolv-toolsbefore 0:0.7.16-3.el8_40:0.7.16-3.el8_4
Red Hat:satellite_capsule:6.11::el7foremanbefore 0:3.1.1.21-2.el7sat0:3.1.1.21-2.el7sat
Red Hat:satellite_capsule:6.11::el7libsolvbefore 0:0.7.22-1.el7pc0:0.7.22-1.el7pc
Red Hat:satellite_capsule:6.11::el7satellitebefore 0:6.11.0-2.el7sat0:6.11.0-2.el7sat
Red Hat:satellite_capsule:6.11::el8foremanbefore 0:3.1.1.21-2.el8sat0:3.1.1.21-2.el8sat
Red Hat:satellite_capsule:6.11::el8libsolvbefore 0:0.7.22-1.el8pc0:0.7.22-1.el8pc
Red Hat:satellite_capsule:6.11::el8python-djangobefore 0:3.2.13-1.el8pc0:3.2.13-1.el8pc
Red Hat:satellite_capsule:6.11::el8python-lxmlbefore 0:4.7.1-1.el8pc0:4.7.1-1.el8pc
Red Hat:satellite_capsule:6.11::el8python-sqlparsebefore 0:0.4.2-2.el8pc0:0.4.2-2.el8pc
Red Hat:satellite_capsule:6.11::el8python38-djangobefore 0:3.2.13-1.el8pc0:3.2.13-1.el8pc
Red Hat:satellite_capsule:6.11::el8satellitebefore 0:6.11.0-2.el8sat0:6.11.0-2.el8sat

+13

Other highest-scoring records for the same primary product.

  • CVE-2026-48864Libsolv: heap buffer overflow in libsolv repopagestore via unchecked decompression of malicious .solv page data
    31Monitor
  • CVE-2019-20387repodata_schema2id in repodata.c in libsolv before 0.7.6 has a heap-based buffer over-read via a last schema whose length is less than the l
    31Monitor
  • CVE-2026-48863Libsolv: stack-based buffer overflow in libsolv eddsa pgp signature verification allows denial of service
    30Monitor
  • CVE-2021-33930Buffer overflow vulnerability in function pool_installable_whatprovides in src/repo.h in libsolv before 0.7.17 allows attackers to cause a D
    30Monitor
  • CVE-2021-33929Buffer overflow vulnerability in function pool_disabled_solvable in src/repo.h in libsolv before 0.7.17 allows attackers to cause a Denial o
    30Monitor
  • CVE-2021-33928Buffer overflow vulnerability in function pool_installable in src/repo.h in libsolv before 0.7.17 allows attackers to cause a Denial of Serv
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
almalinux:libsolv-devel0.7.16-3.el8_4 · AlmaLinux:8Package registry (OSV)
almalinux:libsolv-tools0.7.16-3.el8_4 · AlmaLinux:8Package registry (OSV)
debian:libsolv0.7.17-1 · Debian:12Package registry (OSV)
red hat:foreman0:3.1.1.21-2.el7sat · Red Hat:satellite_capsule:6.11::el7Package registry (OSV)
red hat:libsolv0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:libsolv-debuginfo0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:libsolv-debugsource0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:libsolv-demo-debuginfo0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:libsolv-devel0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::crbPackage registry (OSV)
red hat:libsolv-tools0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::crbPackage registry (OSV)
red hat:libsolv-tools-debuginfo0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:perl-solv-debuginfo0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:python3-solv0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:python3-solv-debuginfo0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:ruby-solv-debuginfo0:0.7.16-3.el8_4 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
rocky linux:libdb0:5.3.28-42.el8_4 · Rocky Linux:8Package registry (OSV)
rocky linux:libsolv0:0.7.16-3.el8_4 · Rocky Linux:8Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

All records