#VU59877 NULL pointer dereference in BusyBox - CVE-2021-42376

Vulnerability identifier: #VU59877

Vulnerability risk: Low

CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-42376

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

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

Vendor: busybox.net

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in Busybox's hush applet when processing a crafted shell command with a \x03 delimiter character. A local user can pass specially crafted string to the affected applet and crash the application.

Mitigation
Install update from vendor's website.

Vulnerable software versions

BusyBox: 1.16.0 - 1.33.1

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External links
https://jfrog.com/blog/unboxing-busybox-14-new-vulnerabilities-uncovered-by-claroty-and-jfrog/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6T2TURBYYJGBMQTTN2DSOAIQGP7WCPGV/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UQXGOGWBIYWOIVXJVRKHZR34UMEHQBXS/
https://security.netapp.com/advisory/ntap-20211223-0002/

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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.