#VU83930 NULL pointer dereference in cryptography - CVE-2023-49083

Vulnerability identifier: #VU83930

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-2023-49083

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
cryptography
Universal components / Libraries / Programming Languages & Components

Vendor: Сryptography

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 when calling the load_pem_pkcs7_certificates() or load_der_pkcs7_certificates() functions. A remote attacker can pass specially crafted PKCS7 blob/certificate certificate to the application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

cryptography: 40.0.0 - 41.0.5

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External links
https://github.com/pyca/cryptography/security/advisories/GHSA-jfhm-5ghh-2f97
https://github.com/pyca/cryptography/pull/9926
https://github.com/pyca/cryptography/commit/f09c261ca10a31fe41b1262306db7f8f1da0e48a

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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.