-------- Forwarded Message --------
Subject: [Security-announce][CVE-2025-8194] Tarfile infinite loop during
parsing with negative member offset
Date: Mon, 28 Jul 2025 18:44:01 +0000
From: Seth Larson <s...@python.org>
Reply-To: security-...@python.org
To: security-annou...@python.org
There is a HIGH severity vulnerability affecting {project}.
There is a defect in the CPython “tarfile” module affecting the “TarFile”
extraction and entry enumeration APIs. The tar implementation would process tar
archives with negative offsets without error, resulting in an infinite loop and
deadlock during the parsing of maliciously crafted tar archives.
This vulnerability can be mitigated by including the following patch after
importing the “tarfile” module:
import tarfile
def _block_patched(self, count):
if count < 0: # pragma: no cover
raise tarfile.InvalidHeaderError("invalid offset")
return _block_patched._orig_block(self, count)
_block_patched._orig_block = tarfile.TarInfo._block
tarfile.TarInfo._block = _block_patched
Please see the linked CVE ID for the latest information on affected versions:
* https://www.cve.org/CVERecord?id=CVE-2025-8194
* https://github.com/python/cpython/pull/137027
_______________________________________________
Security-announce mailing list -- security-annou...@python.org
https://mail.python.org/mailman3//lists/security-announce.python.org
