CVE-2018-20482

low-risk

Published 2018-12-26

GNU Tar through 1.30, when --sparse is used, mishandles file shrinkage during read access, which allows local users to cause a denial of service (infinite read loop in sparse_dump_region in sparse.c) by modifying a file that is supposed to be archived by a different user's process (e.g., a system backup running as root).

Do I need to act?

0.02% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 4.7/10 Medium

LOCAL / HIGH complexity

Affected Products (4)

Tar

Debian Linux

Leap

Affected Vendors

Debian Gnu Opensuse

References (20)

Patch http://git.savannah.gnu.org/cgit/tar.git/commit/?id=c15c42ccd1e2377945fd0414eca1...

Third Party Advisory http://lists.gnu.org/archive/html/bug-tar/2018-12/msg00023.html

Mailing List http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00077.html

Third Party Advisory http://www.securityfocus.com/bid/106354

Mailing List https://lists.debian.org/debian-lts-announce/2018/12/msg00023.html

Mailing List https://lists.debian.org/debian-lts-announce/2021/11/msg00025.html

Exploit https://news.ycombinator.com/item?id=18745431

Third Party Advisory https://security.gentoo.org/glsa/201903-05

Patch https://twitter.com/thatcks/status/1076166645708668928

Patch https://utcc.utoronto.ca/~cks/space/blog/sysadmin/TarFindingTruncateBug