CVE-2020-9308

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-02-20 · updated 2026-06-17
Weakness: CWE-787

Description

archive_read_support_format_rar5.c in libarchive before 3.4.2 attempts to unpack a RAR5 file with an invalid or corrupted header (such as a header size of zero), leading to a SIGSEGV or possibly unspecified other impact.

Affected products

Canonical Ubuntu Linux: 16.04, 18.04, 19.10
Fedoraproject Fedora: 31, 32
libarchive: from 3.4.0 before 3.4.2 — fixed in 3.4.2

How to fix

Upgrade to a fixed version: libarchive 3.4.2. Check the vendor advisory for mitigations.

References

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20459
https://github.com/libarchive/libarchive/pull/1326
https://github.com/libarchive/libarchive/pull/1326/commits/94821008d6eea81e315c5881cdf739202961040a
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6OTE7GWASH2ZOVG5H3HEN5PR6B3KF7JB/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J76F7VU7HC3GBKG5SAKTRBOFOI3RGO6M/
https://security.gentoo.org/glsa/202003-28
https://usn.ubuntu.com/4293-1/
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=20459
https://github.com/libarchive/libarchive/pull/1326
https://github.com/libarchive/libarchive/pull/1326/commits/94821008d6eea81e315c5881cdf739202961040a
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6OTE7GWASH2ZOVG5H3HEN5PR6B3KF7JB/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/J76F7VU7HC3GBKG5SAKTRBOFOI3RGO6M/

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