CVE-2022-0778 Information

Description

The BN_mod_sqrt() function which computes a modular square root contains a bug that can cause it to loop forever for non-prime moduli. Internally this function is used when parsing certificates that contain elliptic curve public keys in compressed form or explicit elliptic curve parameters with a base point encoded in compressed form. It is possible to trigger the infinite loop by crafting a certificate that has invalid explicit curve parameters. Since certificate parsing happens prior to verification of the certificate signature any process that parses an externally supplied certificate may thus be subject to a denial of service attack. The infinite loop can also be reached when parsing crafted private keys as they can contain explicit elliptic curve parameters. Thus vulnerable situations include: - TLS clients consuming server certificates - TLS servers consuming client certificates - Hosting providers taking certificates or private keys from customers - Certificate authorities parsing certification requests from subscribers - Anything else which parses ASN.1 elliptic curve parameters Also any other applications that use the BN_mod_sqrt() where the attacker can control the parameter values are vulnerable to this DoS issue. In the OpenSSL 1.0.2 version the public key is not parsed during initial parsing of the certificate which makes it slightly harder to trigger the infinite loop. However any operation which requires the public key from the certificate will trigger the infinite loop. In particular the attacker can use a self-signed certificate to trigger the loop during verification of the certificate signature. This issue affects OpenSSL versions 1.0.2 1.1.1 and 3.0. It was addressed in the releases of 1.1.1n and 3.0.2 on the 15th March 2022. Fixed in OpenSSL 3.0.2 (Affected 3.0.03.0.1). Fixed in OpenSSL 1.1.1n (Affected 1.1.1-1.1.1m). Fixed in OpenSSL 1.0.2zd (Affected 1.0.2-1.0.2zc).

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=380085481c64de749a6dd25cdf0bcf4360b30f83 https://www.openssl.org/news/secadv/20220315.txt https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=a466912611aa6cbdf550cd10601390e587451246 https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=3118eb64934499d93db3230748a452351d1d9a65 https://www.debian.org/security/2022/dsa-5103 https://lists.debian.org/debian-lts-announce/2022/03/msg00024.html https://lists.debian.org/debian-lts-announce/2022/03/msg00023.html https://security.netapp.com/advisory/ntap-20220321-0002/ https://lists.fedoraproject.org/archives/list/[email protected]/message/GDB3GQVJPXJE7X5C5JN6JAA4XUDWD6E6/ https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2022-0002 https://www.tenable.com/security/tns-2022-06 https://www.tenable.com/security/tns-2022-07 https://lists.fedoraproject.org/archives/list/[email protected]/message/323SNN6ZX7PRJJWP2BUAFLPUAE42XWLZ/ https://lists.fedoraproject.org/archives/list/[email protected]/message/W6K3PR542DXWLEFFMFIDMME4CWMHJRMG/ https://www.tenable.com/security/tns-2022-08 https://www.oracle.com/security-alerts/cpuapr2022.html https://www.tenable.com/security/tns-2022-09 https://security.netapp.com/advisory/ntap-20220429-0005/ https://support.apple.com/kb/HT213256 https://support.apple.com/kb/HT213255 https://support.apple.com/kb/HT213257 http://seclists.org/fulldisclosure/2022/May/38 http://seclists.org/fulldisclosure/2022/May/35 http://seclists.org/fulldisclosure/2022/May/33 http://packetstormsecurity.com/files/167344/OpenSSL-1.0.2-1.1.1-3.0-BN_mod_sqrt-Infinite-Loop.html

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

7.5