ICSA-22-167-14: Siemens OpenSSL Affected Industrial Products

CISA's summary

Summary: A vulnerability in the openSSL component (CVE-2022-0778, [0]) could allow an attacker to create a denial of service condition by providing specially crafted elliptic curve certificates to products that use a vulnerable version of openSSL. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where fixes are not, or not yet available. [0] https://www.openssl.org/news/secadv/20220315.txt

Products, as the advisory lists them

The advisory lists more products than DeSpy shows.

DeSpy has not checked any unit, hardware revision or firmware.

Vulnerabilities in this advisory

• CVE-2022-0778 — CVE-2022-0778 · CWE-835

  The BN_mod_sqrt() function in openSSL, 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.

Acknowledgments, as the advisory lists them

• Siemens ProductCERT: reported this vulnerability to CISA.

The advisory's legal notice

The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use.

Sources

• The advisory at cisa.gov
• The CSAF document (JSON)

DeSpy's copy of this version is dated 2026-09-28.