CVE-2025-52494
Adacore Ada Web Server (AWS) TLS ClientHello Message DoS
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.
INFO
Published Date :
Sept. 3, 2025, 6:15 p.m.
Last Modified :
Sept. 4, 2025, 3:35 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2025-52494
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Ada Web Server to version 25.2 or later.
- Apply relevant security patches from Adacore.
- Configure appropriate SSL handshake timeouts.
- Monitor server thread utilization.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-52494.
| URL | Resource |
|---|---|
| https://adacore.com | |
| https://docs.adacore.com/corp/security-advisories/SEC.AWS-0095-v1.pdf |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-52494 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-52494
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-52494 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-52494 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 03, 2025
Action Type Old Value New Value Added 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. Added Reference https://adacore.com Added Reference https://docs.adacore.com/corp/security-advisories/SEC.AWS-0095-v1.pdf -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 03, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-400 Added CWE CWE-770