CVE-2025-52494: High severity AdaCore Ada Web Server vulnerability
Adacore Ada Web Server (AWS) before 25.2 is vulnerable to a denial-of-service (DoS) condition due to improper handling of SSL handshakes during connection initialization. When a client initiates an HTTPS connection, the server performs the SSL handshake before assigning the connection to a processing slot. However, there is no specific timeout set for this phase, and the server uses the default socket timeout, which is effectively infinite. An attacker can exploit this by sending a malformed TLS ClientHello message with incorrect length values. This causes the server to wait indefinitely for data that never arrives, blocking the worker thread (Line) handling the connection. By opening multiple such connections, up to the server's maximum limit, the attacker can exhaust all available working threads, preventing the server from handling new, legitimate requests.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-52494?
CVE-2025-52494 has been classified as a high severity vulnerability due to its potential to cause a denial-of-service condition.
How do I fix CVE-2025-52494?
To fix CVE-2025-52494, upgrade to Adacore Ada Web Server version 25.2 or later.
What systems are impacted by CVE-2025-52494?
CVE-2025-52494 affects Adacore Ada Web Server versions prior to 25.2.
What type of attack is possible with CVE-2025-52494?
CVE-2025-52494 enables attackers to perform denial-of-service attacks by exploiting improper SSL handshake handling.
When was CVE-2025-52494 disclosed?
CVE-2025-52494 was disclosed in 2025.