| Name | CVE-2023-42118 |
| Description | Exim libspf2 Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Exim libspf2. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the parsing of SPF macros. When parsing SPF macros, the process does not properly validate user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the service account.
. Was ZDI-CAN-17578. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1053870 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| libspf2 (PTS) | jessie, jessie (lts) | 1.2.10-5+deb8u2 | vulnerable |
| stretch (security), stretch (lts), stretch | 1.2.10-7+deb9u2 | vulnerable |
| buster (security), buster, buster (lts) | 1.2.10-7.1~deb10u1 | vulnerable |
| bullseye (security), bullseye | 1.2.10-7.1~deb11u1 | vulnerable |
| bookworm | 1.2.10-7.2 | vulnerable |
| sid, trixie | 1.2.10-8.2 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| libspf2 | source | jessie | (unfixed) | end-of-life | | |
| libspf2 | source | (unstable) | (unfixed) | | | 1053870 |
Notes
[bookworm] - libspf2 <postponed> (Revisit once upstream and ZDI status is clarfied)
[bullseye] - libspf2 <postponed> (Revisit once upstream and ZDI status is clarfied)
[buster] - libspf2 <postponed> (Revisit once upstream and ZDI status is clarfied)
https://www.zerodayinitiative.com/advisories/ZDI-23-1472/
https://bugs.exim.org/show_bug.cgi?id=3032
https://www.openwall.com/lists/oss-security/2023/09/29/5
https://www.openwall.com/lists/oss-security/2023/10/01/4
https://exim.org/static/doc/security/CVE-2023-zdi.txt
https://lists.exim.org/lurker/message/20231004.080103.8c98192c.en.html
Potentially same issue as: https://github.com/shevek/libspf2/issues/45
https://github.com/shevek/libspf2/pull/44
The potentially related (but unknown if exploitable) integer overflow flaw from pull/44
is fixed with libspf2/1.2.10-8. There have been 1. no proofs it is exploitable, and the
finder clarifies as "ut I haven't been able to get it to do anything after that because
another buffer fills up." and 2. that this is the same issue as CVE-2023-42118 .
[stretch] - libspf2 <postponed> (Revisit once upstream and ZDI status is clarfied)