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Fencer Vulns
high 7.5

CVE-2021-33938 json

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

published 2021-09-02 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-20609

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 73%
public exploits
0
none known

Summary

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.

Patch / fix

  • libsolv Debian 14, Debian 13, Debian 12 0.7.17-1

debian advisories DEBIAN-CVE-2021-33938

  • foreman satellite utils 6.11, satellite capsule 6.11, satellite 6.11 3.1.1.21-2.el7sat
  • foreman satellite utils 6.11, satellite capsule 6.11, satellite 6.11 3.1.1.21-2.el8sat
  • libsolv satellite capsule 6.11, satellite 6.11 0.7.22-1.el7pc
  • libsolv satellite capsule 6.11, satellite 6.11 0.7.22-1.el8pc
  • candlepin satellite 6.11 4.1.13-1.el7sat
  • candlepin satellite 6.11 4.1.13-1.el8sat
  • satellite satellite utils 6.11, satellite capsule 6.11, satellite 6.11 6.11.0-2.el7sat
  • satellite satellite utils 6.11, satellite capsule 6.11, satellite 6.11 6.11.0-2.el8sat

red hat advisories RHSA-2022:5498RHSA-2021:4060

  • libsolv-tools AlmaLinux 8 0.7.16-3.el8_4

almalinux advisories ALSA-2021:4060

  • libdb Rocky Linux 8 5.3.28-42.el8_4
  • libsolv Rocky Linux 8 0.7.16-3.el8_4

rocky linux advisories RLSA-2022:5498RLSA-2021:4060

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-2021-33938 updated cvss 7.5

libsolv: heap-based buffer overflow in prune_to_recommended() in src/policy.c

  • Red Hat Enterprise Linux 7 libsolv, libsolv-demo, python2-solv, libsolv-tools
    affected: no fix planned “Out of support scope”
  • Red Hat Update Infrastructure 3 for Cloud Providers libsolv
    affected: no fix planned “Will not fix”
  • Red Hat CodeReady Linux Builder (v. 8) libsolv-tools 0.7.16-3.el8_4 Red Hat Enterprise Linux BaseOS (v. 8) libsolv 0.7.16-3.el8_4, python3-solv 0.7.16-3.el8_4
    fixed: vendor fix RHSA-2021:4060
  • Red Hat Satellite 6.11 for RHEL 7 libsolv 0.7.22-1.el7pc Red Hat Satellite 6.11 for RHEL 8 libsolv 0.7.22-1.el8pc
    fixed: vendor fix RHSA-2022:5498
  • Red Hat Ansible Automation Platform 1.2 libsolv Red Hat Enterprise Linux 9 libsolv, python3-solv, libsolv-tools Red Hat Satellite 6.11 for RHEL 7 tfm 7.0-1.el7sat, gofer 2.12.5-7.el7sat, katello 4.3.0-3.el7sat, libcomps 0.1.18-1.el7pc, libsolv0 0.6.34-4.el7sat, python-qpid 1.35.0-5.el7, +637 more Red Hat Satellite 6.11 for RHEL 8 libdb 5.3.28-42.el8_4, katello 4.3.0-3.el8sat, libcomps 0.1.18-1.el8pc, python-idna 3.3-1.el8pc, python-pbr 5.6.0-1.el8pc, python-qpid 1.37.0-1.el8, +628 more
    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

1.42% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/openSUSE/libsolv/issues/420 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness

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.