Executive brief
TinyWeb, a lightweight web server, is vulnerable to a flaw that allows an unauthenticated remote attacker to crash the service. By sending a specially crafted, malformed web request, an attacker can force the server's background processes to fail. If repeated, this attack takes the entire server offline, requiring a manual restart to restore operations.
Technical details
A NULL pointer dereference exists in TinyWeb through version 0.0.8 within the HTTP parsing and response logic. When `HttpParser::execute()` encounters an invalid HTTP version string (e.g., 'XTTP/1.1'), it fails to allocate the `Url` object and returns an error. However, `WebProtocol::dataReceived()` ignores this error state and proceeds to call `buildResponse()`, which attempts to dereference the uninitialized (NULL) `url` pointer. This results in a SIGSEGV crash of the worker process. An unauthenticated remote attacker can exhaust the worker pool with a small number of requests, leading to a persistent denial-of-service (DoS) condition until the service is manually restarted.
Affected products
- GeneralSandman TinyWeb 0.0.8 and all commits from e48f15d through a381da2
Timeline
- 2026-07-28: disclosed: Vulnerability disclosed by researcher Theodosis Paidakis
- 2026-07-28: advisory: NVD and VulnCheck published advisories