| Name | CVE-2018-9251 |
| Description | The xz_decomp function in xzlib.c in libxml2 2.9.8, if --with-lzma is used, allows remote attackers to cause a denial of service (infinite loop) via a crafted XML file that triggers LZMA_MEMLIMIT_ERROR, as demonstrated by xmllint, a different vulnerability than CVE-2015-8035. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | ELA-46-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| libxml2 (PTS) | jessie, jessie (lts) | 2.9.1+dfsg1-5+deb8u17 | fixed |
| stretch (security) | 2.9.4+dfsg1-2.2+deb9u7 | fixed |
| stretch (lts), stretch | 2.9.4+dfsg1-2.2+deb9u11 | fixed |
| buster, buster (lts) | 2.9.4+dfsg1-7+deb10u9 | fixed |
| buster (security) | 2.9.4+dfsg1-7+deb10u6 | fixed |
| bullseye | 2.9.10+dfsg-6.7+deb11u4 | fixed |
| bullseye (security) | 2.9.10+dfsg-6.7+deb11u5 | fixed |
| bookworm | 2.9.14+dfsg-1.3~deb12u1 | fixed |
| sid, trixie | 2.12.7+dfsg+really2.9.14-0.2 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| libxml2 | source | wheezy | 2.8.0+dfsg1-7+wheezy13 | | ELA-46-1 | |
| libxml2 | source | (unstable) | (not affected) | | | |
Notes
- libxml2 <not-affected> (Fix for CVE-2017-18258 not applied, cf. bug #895195)
https://bugzilla.gnome.org/show_bug.cgi?id=794914
Fixed by: https://gitlab.gnome.org/GNOME/libxml2/commit/2240fbf5912054af025fb6e01e26375100275e74
Before upstream commit https://gitlab.gnome.org/GNOME/libxml2/-/commit/e2a9122b8dde53d320750451e9907a7dcb2ca8bb
the memlimit argument to lzma_auto_decoder was set to UINT64_MAX, possibly
allowing a malicious LZMA compressed files to consume large amounts of memory
when decompressed. Setting memlimit to UINT64_MAX the limiter is effectively
disabled and "lzma_auto_decoder(&state->strm, UINT64_MAX, 0)" can never result
in LZMA_MEMLIMIT_ERROR outcome because there is no way to exceed UINT64_MAX.
Thus CVE-2018-9251 is only affecting libxml2 if e2a9122b8dde53d320750451e9907a7dcb2ca8bb
is applied.