CVE-2025-60753

A vulnerability in apply_substitution() function in libarchive's bsdtar allows crafted -s substitution rules to repeatedly match a zero-length substring and append replacements without advancing the input pointer. When the rule uses the global /g flag (or an explicitly empty pattern), this leads to unbounded output allocation and eventual process OOM (Denial of Service). Upgrade to libarchive 3.8.1 or apply a patch that prevents zero-length match loops or rejects empty patterns.

This vulnerability is rated Moderate rather than Important because its impact is limited to availability and requires user interaction under specific, non-default conditions. Exploitation is only possible when an attacker can directly supply or influence the -s substitution rule passed to bsdtar, which is uncommon in most deployment scenarios since bsdtar is typically invoked with trusted command-line arguments in controlled environments. The flaw does not enable memory corruption, arbitrary code execution, or privilege escalation—it solely results in an infinite loop and memory exhaustion (OOM) leading to a process crash.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.