CVE-2024-41996: Diffie-Hellman Key Exchange Project Diffie-Hellman Key Exchange

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

Validating the order of the public keys in the Diffie-Hellman Key Agreement Protocol, when an approved safe prime is used, allows remote attackers (from the client side) to trigger unnecessarily expensive server-side DHE modular-exponentiation calculations. The client may cause asymmetric resource consumption. The basic attack scenario is that the client must claim that it can only communicate with DHE, and the server must be configured to allow DHE and validate the order of the public key.

Affected products

Diffie-Hellman Key Exchange Project Diffie-Hellman Key Exchange: any version
Siemens Ruggedcom RST2428P: before V3.3 (fixed in V3.3)
Siemens Scalance Xc-300/xr-300/xc-400/xr-500wg/xr-500 Family: before V3.3 (fixed in V3.3)
Siemens Scalance XCH328: before V3.3 (fixed in V3.3)
Siemens Scalance XCM324: before V3.3 (fixed in V3.3)
Siemens Scalance XCM328: before V3.3 (fixed in V3.3)
Siemens Scalance XCM332: before V3.3 (fixed in V3.3)
Siemens Scalance XRH334 24 V Dc, 8xfo, Cc: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 230 V Ac, 12xfo: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 230 V Ac, 8xfo: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 230v Ac, 2x10g, 24xsfp, 8xsfp+: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 24 V Dc, 12xfo: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 24 V Dc, 8xfo: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 24v Dc, 2x10g, 24xsfp, 8xsfp+: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 2x230 V Ac, 12xfo: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 2x230 V Ac, 8xfo: before V3.3 (fixed in V3.3)
Siemens Scalance XRM334 2x230v Ac, 2x10g, 24xsfp, 8xsfp+: before V3.3 (fixed in V3.3)
Siemens Sidis Prime: before V4.0.800 (fixed in V4.0.800)
Siemens SIMATIC s7-1500 TM Mfp - Gnu/linux Subsystem: any version

Published 2024-08-26. Last modified 2026-06-17.