CVE-2021-33683: SAP Internet Communication Manager

Medium severity, CVSS 4.3. EPSS: 0.5% chance of exploitation in the next 30 days.

SAP Web Dispatcher and Internet Communication Manager (ICM), versions - KRNL32NUC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL32UC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL64NUC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, KRNL64UC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, 7.53, 7.73, WEBDISP 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, KERNEL 7.21, 7.22, 7.49, 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, process invalid HTTP header. The incorrect handling of the invalid Transfer-Encoding header in a particular manner leads to a possibility of HTTP Request Smuggling attack. An attacker could exploit this vulnerability to bypass web application firewall protection, divert sensitive data such as customer requests, session credentials, etc.

Affected products

• SAP Internet Communication Manager: version 7.21ext only; version 7.22 only; version 7.22ext only; version 7.49 only; version 7.53 only; version 7.73 only; …
• SAP Web Dispatcher: version 7.8_kernel_7.21 only; version 7.21ext only; version 7.22 only; version 7.22ext only; version 7.49 only; version 7.53 only; …

Published 2021-07-14. Last modified 2026-06-17.