#VU55853 Integer overflow in cpio - CVE-2021-38185

Vulnerability identifier: #VU55853

Vulnerability risk: High

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2021-38185

CWE-ID: CWE-190

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
cpio
Client/Desktop applications / Software for archiving

Vendor: GNU

Description

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

The vulnerability exists due to integer overflow in the "ds_fgetstr" parameter in "dstring.c". A remote attacker can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

cpio: 2.5 - 2.13

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External links
https://github.com/fangqyi/cpiopwn
https://lists.gnu.org/archive/html/bug-cpio/2021-08/msg00002.html
https://lists.gnu.org/archive/html/bug-cpio/2021-08/msg00000.html
https://git.savannah.gnu.org/cgit/cpio.git/commit/?id=dd96882877721703e19272fe25034560b794061b

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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. However, proof of concept for this vulnerability is available.