Race condition in zstd (Alpine package)

1) Race condition

EUVDB-ID: #VU20060

Risk: Medium

CVSSv4.0: 4.8 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-11922

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows an attacker to execute arbitrary code on the target system.

The vulnerability exists due to a race condition in the one-pass compression functions. A remote attacker can exploit the race and write bytes out of bounds if an output buffer smaller than the recommended size was used.

Successful exploitation of the vulnerability may allow an attacker to execute arbitrary code on the target system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

zstd (Alpine package): 1.3.2-r0 - 1.4.4-r1

CPE2.3

• cpe:2.3:a:alpine:zstd_alpine_package:1.3.2-r0:*:*:*:*:alpine_linux:*:3.7
• cpe:2.3:a:alpine:zstd_alpine_package:1.3.3-r0:*:*:*:*:alpine_linux:*:3.7
• cpe:2.3:a:alpine:zstd_alpine_package:1.3.3-r1:*:*:*:*:alpine_linux:*:3.7

External links

https://git.alpinelinux.org/aports/commit/?id=c773d6d0d9b2afa790264a4aa5d455843e139d84
https://git.alpinelinux.org/aports/commit/?id=13b21dfeb82642af3f85e8ef5a1352845d426be4

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.