CVE-2025-52494 Denial of service in n/a
An attacker can cause a denial of service in Ada Web Server by exhausting worker threads through malformed TLS handshakes that lack proper timeouts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-52494?
CVE-2025-52494 is a high-severity denial of service vulnerability in n/a, published on 3 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2025-52494?
It affects 1 product.
Products include Adacore Ada Web Server.
How do I fix CVE-2025-52494?
No fix has been published for CVE-2025-52494 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-52494 being exploited?
There is no known exploitation of CVE-2025-52494 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as GHSA-pvqr-qr3w-3jpg.