#VU37107 Out-of-bounds read in DISCOUNT and Debian Linux - CVE-2018-11503

Vulnerability identifier: #VU37107

Vulnerability risk: Medium

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-11503

CWE-ID: CWE-125

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
DISCOUNT
Client/Desktop applications / Other client software
Debian Linux
Operating systems & Components / Operating system

Vendor: John Gruber
Debian

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error in The isfootnote function in markdown.c in libmarkdown.a in DISCOUNT 2.2.3a. A remote attacker can perform a denial of service (heap-based buffer over-read) via a crafted file, as demonstrated by mkd2html.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

DISCOUNT: 2.2.3

Debian Linux: 2.2.3 - 9.0

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External links
https://github.com/Orc/discount/issues/189#issuecomment-392247798
https://lists.debian.org/debian-lts-announce/2018/09/msg00009.html
https://www.debian.org/security/2018/dsa-4293

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.