Out-of-bounds write in json-c (Alpine package)

1) Out-of-bounds write

EUVDB-ID: #VU27882

Risk: High

CVSSv4.0: 7.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2020-12762

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a boundary error when processing untrusted input in the "printbuf_memappend". A remote attacker can create a specially crafted JSON file, trick the victim into opening it using the affected software, trigger out-of-bounds write and execute arbitrary code on the target system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

json-c (Alpine package): 0.10-r0 - 0.13.1-r0

CPE2.3

• cpe:2.3:a:alpine:json-c_alpine_package:0.10-r0:*:*:*:*:alpine_linux:*:2.6
• cpe:2.3:a:alpine:json-c_alpine_package:0.11-r0:*:*:*:*:alpine_linux:*:2.6
• cpe:2.3:a:alpine:json-c_alpine_package:0.12-r0:*:*:*:*:alpine_linux:*:2.7

External links

https://git.alpinelinux.org/aports/commit/?id=1521ea69211afec5bb5df602fdaa46a386fff560
https://git.alpinelinux.org/aports/commit/?id=41324979d78576f49133c5a636043f53ea0db823
https://git.alpinelinux.org/aports/commit/?id=f1c627ea77bf1ce0e01d2683b6c3b71443e800fb
https://git.alpinelinux.org/aports/commit/?id=f61203451f6117ba48c80f153b51a87f3ee9cc84
https://git.alpinelinux.org/aports/commit/?id=d378948d72aafb68e0f6ee3abbadfbd33ceda2fa

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.