SAP Approuter Request Smuggling and Redirect Flaws

Request-response desynchronization in SAP Approuter lets an unauthenticated remote attacker send a specially crafted HTTP request that smuggles a second request past the front end, allowing exposure of other users' HTTP responses and denial of service against the application. The flaw carries a CVSS 9.1 (high confidentiality and availability impact) and was reported by SAP; there is no public exploit identified at time of analysis and it is not listed in CISA KEV.

Unauthorized access in SAP Approuter arises because the component fails to validate incoming request headers during the OAuth2 login flow under certain configurations (CWE-601, open redirect). An unauthenticated remote attacker who lures a victim into clicking a crafted link can hijack the authentication flow to gain high-confidentiality and high-integrity access to the application. There is no public exploit identified at time of analysis and the CVE is not listed in CISA KEV, but the network-reachable, low-complexity nature (CVSS 8.1) makes it a meaningful patch priority for SAP BTP/Cloud Foundry environments.