Buffer overflow in brotli (Alpine package)

1) Buffer overflow

EUVDB-ID: #VU46905

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-8927

CWE-ID: CWE-120 - Buffer overflow

Exploit availability: No

Description

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

A buffer overflow exists in the Brotli library versions prior to 1.0.8 where an attacker controlling the input length of a "one-shot" decompression request to a script can trigger a crash, which happens when copying over chunks of data larger than 2 GiB. It is recommended to update your Brotli library to 1.0.8 or later. If one cannot update, we recommend to use the "streaming" API as opposed to the "one-shot" API, and impose chunk size limits.

Mitigation

Install update from vendor's website.

Vulnerable software versions

samba (Alpine package): 4.1.1-r0 - 4.12.7-r0

brotli (Alpine package): 1.0.7-r5 - 1.0.9-r2

RoboHelp: 0.60.6-r0

CPE2.3

• cpe:2.3:a:alpine:samba_alpine_package:4.1.1-r0:*:*:*:*:alpine_linux:*:2.6
• cpe:2.3:a:alpine:samba_alpine_package:4.1.3-r0:*:*:*:*:alpine_linux:*:2.6
• cpe:2.3:a:alpine:samba_alpine_package:4.1.3-r1:*:*:*:*:alpine_linux:*:2.6
• cpe:2.3:a:alpine:brotli_alpine_package:1.0.7-r5:*:*:*:*:alpine_linux:*:3.12
• cpe:2.3:a:alpine:brotli_alpine_package:1.0.9-r0:*:*:*:*:alpine_linux:*:3.12
• cpe:2.3:a:alpine:brotli_alpine_package:1.0.9-r1:*:*:*:*:alpine_linux:*:3.12
• cpe:2.3:a:adobe:robohelp:0.60.6-r0:*:*:*:*:alpine_linux:*:1.9

External links

https://git.alpinelinux.org/aports/commit/?id=5967ccb266b4ee3c668194c7fdc7cafa5c5e9a02

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.