Description
mspack/lzxd.c in libmspack 0.5alpha, as used in ClamAV 0.99.2, allows remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted CHM file.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | clamav | 0.99.3~beta1+dfsg-1 | — |
| Debian 14 | libmspack | 0.6-1 | — |
| Debian 13 | clamav | 0.99.3~beta1+dfsg-1 | — |
| Debian 13 | libmspack | 0.6-1 | — |
| Debian 12 | clamav | 0.99.3~beta1+dfsg-1 | — |
| Debian 12 | libmspack | 0.6-1 | — |
| Debian 9 | libmspack | 0.5-1+deb9u1 | DSA-3946-1 |
| Debian 8 | libmspack | 0.5-1+deb8u1 | DSA-3946-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 7 | clamav | 0.99.2+dfsg-0+deb7u5 | DLA-1279-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | clamav | 0.99.2+dfsg-0ubuntu0.16.04.2 | USN-3393-1 |
| Ubuntu 16.04 LTS | libmspack | 0.5-1ubuntu0.16.04.1 | USN-3394-1 |
| Ubuntu 14.04 LTS | clamav | 0.99.2+addedllvm-0ubuntu0.14.04.2 | USN-3393-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | libmspack | 0.4-1ubuntu0.1~esm2 | USN-7788-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0809-1, SUSE-SU-2018:0255-1 |
| SLES 12 SP2 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0809-1, SUSE-SU-2018:0255-1 |
| SLES 12 SP1 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0255-1 |
| SLES 12 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0255-1 |
| SLES 11 SP4 | clamav | 0.99.3-0.20.3.2 | SUSE-SU-2018:0863-1, SUSE-SU-2018:0254-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 11 SP3 | clamav | 0.99.3-0.20.3.2 | SUSE-SU-2018:0863-1, SUSE-SU-2018:0254-1 |
| SLES for SAP 12 SP3 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0809-1, SUSE-SU-2018:0255-1 |
| SLES for SAP 12 SP2 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0809-1, SUSE-SU-2018:0255-1 |
| SLES for SAP 12 SP1 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0255-1 |
| SLES for SAP 12 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0255-1 |
| SLES for SAP 11 SP4 | clamav | 0.99.3-0.20.3.2 | SUSE-SU-2018:0863-1, SUSE-SU-2018:0254-1 |
| SUSE OpenStack Cloud 6 | clamav | 0.99.3-33.5.1 | SUSE-SU-2018:0255-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | clamav | 0.99.3-0.20.3.2 | SUSE-SU-2018:0863-1, SUSE-SU-2018:0254-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | clamav | 0.103.3-1.4 | openSUSE-SU-2024:10685-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | clamav | 0.99.4-r0 | — |
| Alpine v3.24 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.23 | clamav | 0.99.4-r0 | — |
| Alpine v3.23 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.22 | clamav | 0.99.4-r0 | — |
| Alpine v3.22 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.21 | clamav | 0.99.4-r0 | — |
| Alpine v3.21 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.20 | clamav | 0.99.4-r0 | — |
| Alpine v3.20 | libmspack | 0.5_alpha-r1 | — |
Show 17 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | clamav | 0.99.4-r0 | — |
| Alpine v3.19 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.18 | clamav | 0.99.4-r0 | — |
| Alpine v3.18 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.17 | clamav | 0.99.4-r0 | — |
| Alpine v3.17 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.16 | clamav | 0.99.4-r0 | — |
| Alpine v3.16 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.15 | clamav | 0.99.4-r0 | — |
| Alpine v3.15 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.14 | clamav | 0.99.4-r0 | — |
| Alpine v3.14 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.13 | clamav | 0.99.4-r0 | — |
| Alpine v3.13 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.12 | clamav | 0.99.4-r0 | — |
| Alpine v3.12 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.11 | clamav | 0.99.4-r0 | — |
| Alpine v3.11 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.10 | clamav | 0.99.4-r0 | — |
| Alpine v3.10 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.9 | clamav | 0.99.4-r0 | — |
| Alpine v3.9 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.8 | clamav | 0.99.4-r0 | — |
| Alpine v3.8 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.7 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.6 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.5 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.4 | libmspack | 0.5_alpha-r1 | — |
| Alpine v3.3 | libmspack | 0.5_alpha-r1 | — |
Advisories 10
- USN-7788-1 libmspack vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3393-1 clamav vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3394-1 libmspack vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-3946-1 libmspack - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1279-1 clamav - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10685-1 clamav-0.103.3-1.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0254-1 Security update for clamav SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0863-1 Security update for clamav SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0809-1 Security update for clamav SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0255-1 Security update for clamav SUSE / openSUSE Security Updates · May 2, 2025
References
- [debian-lts-announce] 20180212 [SECURITY] [DLA 1279-1] clamav security update mailing-list
- DSA-3946 vendor-advisory
- https://github.com/varsleak/varsleak-vul/blob/master/clamav-vul/heap-overflow/clamav_chm_crash.md
- https://bugzilla.clamav.net/show_bug.cgi?id=11701
- GLSA-201804-16 vendor-advisory
- https://github.com/vrtadmin/clamav-devel/commit/a83773682e856ad6529ba6db8d1792e6d515d7f1