--- title: "CVE-2022-0778: Infinite loop in BN_mod_sqrt() reachable… | CubePath" 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…" language: en source: https://cubepath.com/security/cve/CVE-2022-0778 --- # CVE-2022-0778: Infinite loop in BN_mod_sqrt() reachable… | CubePath ## 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 3.0.0,3.0.1). 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). Official description from the CVE record, published by openssl. Copyright © 1999-2026 The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CVE license. [View the record on cve.org](https://www.cve.org/CVERecord?id=CVE-2022-0778) ## Key data ### CVSS 3.1 High 7.5 Score published by CISA-ADP in the CVE record. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | Metric | Value | What it means | | ---------------------- | --------- | ----------------------------------------------------------------------------------- | | Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. | | Attack complexity | Low | No special conditions are needed. The attack can be repeated at will. | | Privileges required | None | No account or privileges are needed. | | User interaction | None | No action from any user is needed. | | Scope | Unchanged | The impact stays within the vulnerable component. | | Confidentiality impact | None | No effect on the secrecy of data. | | Integrity impact | None | No effect on the trustworthiness of data. | | Availability impact | High | Serious or total effect on availability. | CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at [first.org/cvss](https://www.first.org/cvss/) . ### EPSS Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days. Score 0.73188 (73.2% probability) Percentile 99.5% Scores of Nov 10, 2026 Model v2026.06.15 ### CISA assessment as of May 22, 2026 Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA. Automatable yes Technical impact partial ### Weakness (CWE) CWE catalog version 5.0. CWE names: Copyright © 2006-2026, The MITRE Corporation. See [/security/cve/legal](https://cubepath.com/security/cve/legal) for the CWE license. - [CWE-835](https://cwe.mitre.org/data/definitions/835.html) Loop with Unreachable Exit Condition ## Affected products Products listed in the CVE record, as the CNA published them. - OpenSSL - affected: Fixed in OpenSSL 3.0.2 (Affected 3.0.0,3.0.1) - affected: Fixed in OpenSSL 1.1.1n (Affected 1.1.1-1.1.1m) - affected: Fixed in OpenSSL 1.0.2zd (Affected 1.0.2-1.0.2zc) ## References Links listed in the CVE record. They lead to other sites, which CubePath does not control. - [openssl.org/news/secadv/20220315.txt](https://www.openssl.org/news/secadv/20220315.txt) - [git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=a4…](https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=a466912611aa6cbdf550cd10601390e587451246) - [git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=31…](https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=3118eb64934499d93db3230748a452351d1d9a65) - [git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=38…](https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=380085481c64de749a6dd25cdf0bcf4360b30f83) - [DSA-5103](https://www.debian.org/security/2022/dsa-5103) (debian.org) vendor-advisory - [\[debian-lts-announce\] 20220317 \[SECURITY\] \[DLA 2952-1\] openssl security update](https://lists.debian.org/debian-lts-announce/2022/03/msg00023.html) (lists.debian.org) mailing-list - [\[debian-lts-announce\] 20220317 \[SECURITY\] \[DLA 2953-1\] openssl1.0 security update](https://lists.debian.org/debian-lts-announce/2022/03/msg00024.html) (lists.debian.org) mailing-list - [FEDORA-2022-a5f51502f0](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GDB3GQVJPXJE7X5C5JN6JAA4XUDWD6E6/) (lists.fedoraproject.org) vendor-advisory - [FEDORA-2022-9e88b5d8d7](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/323SNN6ZX7PRJJWP2BUAFLPUAE42XWLZ/) (lists.fedoraproject.org) vendor-advisory - [FEDORA-2022-8bb51f6901](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W6K3PR542DXWLEFFMFIDMME4CWMHJRMG/) (lists.fedoraproject.org) vendor-advisory - [oracle.com/security-alerts/cpuapr2022.html](https://www.oracle.com/security-alerts/cpuapr2022.html) - [security.netapp.com/advisory/ntap-20220321-0002](https://security.netapp.com/advisory/ntap-20220321-0002/) - [psirt.global.sonicwall.com/vuln-detail/SNWLID-2022-0002](https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2022-0002) - [tenable.com/security/tns-2022-06](https://www.tenable.com/security/tns-2022-06) - [tenable.com/security/tns-2022-07](https://www.tenable.com/security/tns-2022-07) - [tenable.com/security/tns-2022-08](https://www.tenable.com/security/tns-2022-08) - [20220516 APPLE-SA-2022-05-16-4 Security Update 2022-004 Catalina](http://seclists.org/fulldisclosure/2022/May/33) (seclists.org) mailing-list - [20220516 APPLE-SA-2022-05-16-3 macOS Big Sur 11.6.6](http://seclists.org/fulldisclosure/2022/May/35) (seclists.org) mailing-list - [20220516 APPLE-SA-2022-05-16-2 macOS Monterey 12.4](http://seclists.org/fulldisclosure/2022/May/38) (seclists.org) mailing-list - [oracle.com/security-alerts/cpujul2022.html](https://www.oracle.com/security-alerts/cpujul2022.html) - [support.apple.com/kb/HT213257](https://support.apple.com/kb/HT213257) - [support.apple.com/kb/HT213256](https://support.apple.com/kb/HT213256) - [support.apple.com/kb/HT213255](https://support.apple.com/kb/HT213255) - [tenable.com/security/tns-2022-09](https://www.tenable.com/security/tns-2022-09) - [security.netapp.com/advisory/ntap-20220429-0005](https://security.netapp.com/advisory/ntap-20220429-0005/) - [packetstormsecurity.com/files/167344/OpenSSL-1.0.2-1.1.1-3.…](http://packetstormsecurity.com/files/167344/OpenSSL-1.0.2-1.1.1-3.0-BN%5Fmod%5Fsqrt-Infinite-Loop.html) - [cert-portal.siemens.com/productcert/pdf/ssa-712929.pdf](https://cert-portal.siemens.com/productcert/pdf/ssa-712929.pdf) - [GLSA-202210-02](https://security.gentoo.org/glsa/202210-02) (security.gentoo.org) vendor-advisory - [security.netapp.com/advisory/ntap-20240621-0006](https://security.netapp.com/advisory/ntap-20240621-0006/) ## Timeline 1. ID reserved Feb 28, 2022 2. Record published Mar 15, 2022 3. Record last updated Oct 14, 2026 ## Look up another CVE ## About CubePath CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection. [Cloud VPS](https://cubepath.com/vps) [DDoS protection](https://cubepath.com/ddos-protection) Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 20:01 UTC. [Sources and licenses](https://cubepath.com/security/cve/legal)