PT-2021-6138

CVE-2021-45960

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Published

2021-12-30

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Updated

2026-10-14

Description by

CVSS 3.1
9.8
Critical
MetricsAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Name of the Vulnerable Software and Affected Versions Expat (aka libexpat) versions prior to 2.4.3
Description The issue is related to a left shift by 29 (or more) places in the storeAtts function in xmlparse.c, which can lead to realloc misbehavior, such as allocating too few bytes or only freeing memory. This can cause a denial of service. Additionally, there is a mention of an integer overflow of addBinding in xmlparse.c, which could potentially allow a remote attacker to execute arbitrary code on the system by persuading a victim to open a specially-crafted file.
Recommendations For versions prior to 2.4.3, update to version 2.4.3 or later to resolve the issue. As a temporary workaround, consider disabling the storeAtts function until a patch is available. Restrict access to specially-crafted files to minimize the risk of exploitation.
Exploitability
Exploit
Fix
Impacts
Researchers
Vendors
Affected products
Related identifiers
ALSA-2022:0951
ALT-PU-2022-1072
ALT-PU-2022-1130
ALT-PU-2022-1176
ALT-PU-2023-4107
AZL-7124
CESA-2022_0951
CESA-2022_1069
CLEANSTART-2026-CC51357
CLEANSTART-2026-EM10970
CLEANSTART-2026-MH09144
CLEANSTART-2026-YT18139
DLA-2904-1
DSA-5073-1
MGASA-2022-0031
OESA-2022-1490
OESA-2023-1464
OESA-2023-1465
OESA-2024-1815
OPENSUSE-SU-2022:0178-1
OPENSUSE-SU-2022_0178-1
OPENSUSE-SU-2024:11762-1
RHSA-2022:0951
RHSA-2022_0951
RHSA-2022:1069
RHSA-2022_1069
RLSA-2022:0951
SUSE-SU-2022:0178-1
SUSE-SU-2022_0178-1
SUSE-SU-2022:0179-1
SUSE-SU-2022_0179-1
SUSE-SU-2022:14878-1
SUSE-SU-2022_14878-1
USN-5288-1
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