#VU68858 Off-by-one in libtASN1 - CVE-2021-46848

Vulnerability identifier: #VU68858

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-2021-46848

CWE-ID: CWE-193

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libtASN1
Universal components / Libraries / Libraries used by multiple products

Vendor: GNU

Description

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

The vulnerability exists due to an ETYPE_OK off-by-one error in asn1_encode_simple_der in Libtasn1. A remote attacker can pass specially crafted data to the application, trigger an off-by-one error and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

libtASN1: 4.0 - 4.18.0

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External links
https://gitlab.com/gnutls/libtasn1/-/issues/32
https://gitlab.com/gnutls/libtasn1/-/commit/44a700d2051a666235748970c2df047ff207aeb5

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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.