CVE-2018-18584

Publication date 22 October 2018

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

6.5 · Medium

Score breakdown

In mspack/cab.h in libmspack before 0.8alpha and cabextract before 1.8, the CAB block input buffer is one byte too small for the maximal Quantum block, leading to an out-of-bounds write.

From the Ubuntu Security Team

It was discovered that cabextract incorrectly handled certain malformed CAB files. A remote attacker could use this issue to cause cabextract to crash, resulting in a denial of service.

Read the notes from the security team

Status

Package Ubuntu Release Status
cabextract 22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Not affected
19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
clamav 22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Not affected
19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Fixed 0.100.2+dfsg-1ubuntu0.14.04.2
libmspack 22.04 LTS jammy
Not affected
21.10 impish
Not affected
21.04 hirsute
Not affected
20.10 groovy
Not affected
20.04 LTS focal
Not affected
19.10 eoan
Not affected
19.04 disco
Not affected
18.10 cosmic
Fixed 0.7-1ubuntu0.1
18.04 LTS bionic
Fixed 0.6-3ubuntu0.2
16.04 LTS xenial
Fixed 0.5-1ubuntu0.16.04.3
14.04 LTS trusty

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Notes

alexmurray

We released clamav 0.100.2+dfsg-1ubuntu0.1X.04.2 for precise/esm and trusty, but subsequently were notified the bundled libmspack is not actually vulnerable in this case, as the version of libmspack provided had increased the CAB_BLOCKMAX macro to 65535, meaning that CAB_INPUTMAX is now 71679, which is impossible to encode in the 16-bit cfdata_CompressedSize field of a single block.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
libmspack

Severity score breakdown

Parameter Value
Base score 6.5 · Medium
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

    • USN-3814-1
    • libmspack vulnerabilities
    • 12 November 2018
    • USN-3814-2
    • ClamAV vulnerabilities
    • 13 November 2018
    • USN-3814-3
    • ClamAV vulnerabilities
    • 13 November 2018

Other references