DotVVM is an open source MVVM framework for web applications. Prior to 4.2.11, 4.3.15, and 5.0.0-preview09-final, a route containing multiple unconstrained parameters in one path segment can cause excessive regular-expression backtracking in DotvvmRoute.IsMatch when a remote requester supplies a long near-match path. DotvvmRouteParser.RouteRegex previously had no matching timeout. Patched runtimes retry with the .NET non-backtracking engine, while runtimes that do not support non-backtracking matching return HTTP 503 after the one-second timeout in DotvvmRoutingMiddleware.
This issue is fixed in versions 4.2.11, 4.3.15, and 5.0.0-preview09-final.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 6
https://github.com/riganti/dotvvm/commit/1635245b5eaf9ccf8e3536b9d8b19418195265…
security-advisories@github.com
https://github.com/riganti/dotvvm/commit/4fc26a8591c76fb92ed701352c2a84120cf926…
security-advisories@github.com
https://github.com/riganti/dotvvm/commit/5728ab80fff9af883b44d11c118d2e8a8991dc…
security-advisories@github.com
https://github.com/riganti/dotvvm/releases/tag/v4.3.15
security-advisories@github.com
https://github.com/riganti/dotvvm/releases/tag/v5.0.0-preview09
security-advisories@github.com
https://github.com/riganti/dotvvm/security/advisories/GHSA-c2g3-c4gc-w5wg
security-advisories@github.com