Expat · Expat · CVE-2021-45960
**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.