Actively exploited in the wild
PEAR Archive_Tar Deserialization of Untrusted Data Vulnerability
PEAR - Archive_Tar · Listed in the CISA KEV since 2022-08-25. This indicates confirmed attacks in production environments.
Required action: Apply updates per vendor instructions.
CVE-2020-28949
HighCVSS 7.8KEVSummary
Archive_Tar through 1.4.10 has :// filename sanitization only to address phar attacks, and thus any other stream-wrapper attack (such as file:// to overwrite files) can still succeed.
Risk Assessment
An attacker could exploit this vulnerability to overwrite arbitrary files on the server, potentially leading to code execution or system damage. However, processing a malicious tar archive is required.
Recommendation
Update the Archive_Tar library to a version later than 1.4.10. If update is not possible, avoid processing untrusted tar archives.
Other vulnerabilities in Archive_Tar
See all- CVE-2026-42496Critical
Archive::Tar versions before 3.08 for Perl extract symlinks with attacker controlled targets outside the extraction directory. _make_special_file() passes the tar header's linkname to symlink() without validating it against absolute paths or .. segments. The secure-extract mode check that guards regular file extraction does not cover the symlink target. A subsequent open through the extracted name reads or writes the attacker chosen path.
- CVE-2020-36193HighActively exploited
Tar.php in Archive_Tar through 1.4.11 allows write operations with Directory Traversal due to inadequate checking of symbolic links, a related issue to CVE-2020-28948.
- CVE-2026-9538High
In the Archive::Tar library for Perl versions before 3.10, memory exhaustion is possible via an attacker-controlled entry size field in the tar header. The _read_tar() function allocates a scalar based on the header size without an upper bound.
- CVE-2026-42497High
A vulnerability in Archive::Tar for Perl before version 3.08 allows extraction of hardlinks to attacker-controlled paths outside the extraction directory. The _make_special_file() function passes the tar header's linkname to link() without validating absolute paths or '..' segments, creating a hardlink to the victim file. A subsequent write through the extracted name modifies the victim file, and the _extract_file() block (guarded only against symlinks) applies permissions, owner, and timestamps to the shared inode.
Original NVD description (English source)
Archive_Tar through 1.4.10 has :// filename sanitization only to address phar attacks, and thus any other stream-wrapper attack (such as file:// to overwrite files) can still succeed.