CVE-2021-36976

Name: CVE-2021-36976
Creator: NVD / NIST
Published: 2021-07-20T07:15:07.95+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 2.84%

Last modified Jun 17, 2026

CVE-2021-36976 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. libarchive 3.4.1 through 3.5.1 has a use-after-free in copy_string (called from do_uncompress_block and process_block).. EPSS estimates a 2.84% chance of exploitation in the next 30 days.

Description

libarchive 3.4.1 through 3.5.1 has a use-after-free in copy_string (called from do_uncompress_block and process_block).

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

2.84%

84.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Libarchive	Libarchive	>= 3.4.1, <= 3.5.2
Fedoraproject	Fedora	35
Apple	Ipados	< 15.4
Apple	Iphone Os	< 15.4
Apple	Macos	< 12.3
Apple	Watchos	< 8.5
Splunk	Universal Forwarder	>= 8.2.0, < 8.2.12
Splunk	Universal Forwarder	>= 9.0.0, < 9.0.6
Splunk	Universal Forwarder	9.1.0

References

http://seclists.org/fulldisclosure/2022/Mar/27Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2022/Mar/28Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2022/Mar/29Mailing List, Third Party Advisory
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32375Issue Tracking, Third Party Advisory
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/libarchive/OSV-2021-557.yamlThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SE5NJQNM22ZE5Z55LPAGCUHSBQZBKMKC/Mailing List, Third Party Advisory
https://security.gentoo.org/glsa/202208-26Third Party Advisory
https://support.apple.com/kb/HT213182Third Party Advisory
https://support.apple.com/kb/HT213183Third Party Advisory
https://support.apple.com/kb/HT213193Third Party Advisory
http://seclists.org/fulldisclosure/2022/Mar/27Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2022/Mar/28Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2022/Mar/29Mailing List, Third Party Advisory
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32375Issue Tracking, Third Party Advisory
https://github.com/google/oss-fuzz-vulns/blob/main/vulns/libarchive/OSV-2021-557.yamlThird Party Advisory
https://lists.debian.org/debian-lts-announce/2024/11/msg00007.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SE5NJQNM22ZE5Z55LPAGCUHSBQZBKMKC/Mailing List, Third Party Advisory
https://security.gentoo.org/glsa/202208-26Third Party Advisory
https://support.apple.com/kb/HT213182Third Party Advisory
https://support.apple.com/kb/HT213183Third Party Advisory
https://support.apple.com/kb/HT213193Third Party Advisory

Timeline

Published: Jul 20, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-36976?

libarchive 3.4.1 through 3.5.1 has a use-after-free in copy_string (called from do_uncompress_block and process_block).

How severe is CVE-2021-36976?

CVE-2021-36976 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 2.84% probability of exploitation in the next 30 days.

How do I fix CVE-2021-36976?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-36976?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST