#VU51741 Improper Handling of Exceptional Conditions in BusyBox - CVE-2021-28831

Vulnerability identifier: #VU51741

Vulnerability 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-2021-28831

CWE-ID: CWE-755

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
BusyBox
Universal components / Libraries / Software for developers

Vendor: busybox.net

Description

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

The vulnerability exists due to improper handling of error bit on the huft_build result pointer in decompress_gunzip.c. A remote attacker can pass malformed gzip data to the application, trigger an invalid free and perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

BusyBox: 0.38 - 1.33.0

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External links
https://git.busybox.net/busybox/commit/?id=f25d254dfd4243698c31a4f3153d4ac72aa9e9bd

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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.