| Name | CVE-2018-20482 |
| Description | 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). |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more) |
| References | DLA-1623-1, DLA-2830-1 |
| NVD severity | low |
| Debian Bugs | 917377 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| tar (PTS) | stretch | 1.29b-1.1 | vulnerable |
| stretch (security) | 1.29b-1.1+deb9u1 | fixed | |
| buster | 1.30+dfsg-6 | fixed | |
| bookworm, sid, bullseye | 1.34+dfsg-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| tar | source | jessie | 1.27.1-2+deb8u2 | DLA-1623-1 | ||
| tar | source | stretch | 1.29b-1.1+deb9u1 | DLA-2830-1 | ||
| tar | source | (unstable) | 1.30+dfsg-3.1 | 917377 |
https://utcc.utoronto.ca/~cks/space/blog/sysadmin/TarFindingTruncateBug
https://news.ycombinator.com/item?id=18745431
https://twitter.com/thatcks/status/1076166645708668928
https://lists.gnu.org/archive/html/bug-tar/2018-12/msg00023.html
Fixed by https://git.savannah.gnu.org/cgit/tar.git/commit/?id=c15c42c