#VU66124 NULL pointer dereference in GnuTLS - CVE-2021-4209

Vulnerability identifier: #VU66124

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-2021-4209

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

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

Vendor: GnuTLS

Description

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

The vulnerability exists due to a NULL pointer dereference error in MD_UPDATE. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

GnuTLS: 3.5.0 - 3.7.2

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External links
https://gitlab.com/gnutls/gnutls/-/issues/1306
https://gitlab.com/gnutls/gnutls/-/commit/3db352734472d851318944db13be73da61300568

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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.