Vulnerability in GNU Tar
CVE-2018-20482
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).
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (44.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 44.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- GNU Tar
- Debian Linux — versions 8.0, 9.0
- openSUSE Leap — versions 15.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- utcc.utoronto.ca/~cks/space/blog/sysadmin/TarFindingTruncateBug (Patch, Third Party Advisory)
- git.savannah.gnu.org/cgit/tar.git/commit/ (Patch, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2018/12/msg00023.html (mailing-list, Mailing List, Third Party Advisory)
- news.ycombinator.com/item (Exploit, Third Party Advisory)
- www.securityfocus.com/bid/106354 (VDB Entry, Third Party Advisory, vdb-entry)
- security.gentoo.org/glsa/201903-05 (vendor-advisory, Third Party Advisory)
- lists.gnu.org/archive/html/bug-tar/2018-12/msg00023.html (Third Party Advisory)
- twitter.com/thatcks/status/1076166645708668928 (Patch, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2019-04/msg00077.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/11/msg00025.html (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2018-20482?
- CVE-2018-20482 is a medium-severity vulnerability in GNU Tar, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 4.7/10. Published 2018-12-26.
- How severe is CVE-2018-20482?
- Medium severity. CVSS v3 base score is 4.7 out of 10.
- Is CVE-2018-20482 known to be exploited?
- 7 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.