CVE-2026-28789 in OliveTin
Summary
by MITRE • 03/05/2026
OliveTin gives access to predefined shell commands from a web interface. Prior to version 3000.10.3, an unauthenticated denial-of-service vulnerability exists in OliveTin’s OAuth2 login flow. Concurrent requests to /oauth/login can trigger unsynchronized access to a shared registeredStates map, causing a Go runtime panic (fatal error: concurrent map writes) and process termination. This allows remote attackers to crash the service when OAuth2 is enabled. This issue has been patched in version 3000.10.3.
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Analysis
by VulDB Data Team • 03/10/2026
The vulnerability CVE-2026-28789 represents a critical denial-of-service weakness in OliveTin web application software that affects versions prior to 3000.10.3. This issue specifically targets the OAuth2 authentication mechanism within OliveTin, which provides users with access to predefined shell commands through a web interface. The flaw manifests when multiple concurrent requests are made to the /oauth/login endpoint while OAuth2 functionality is enabled, creating a scenario where the application's internal state management becomes compromised. The vulnerability stems from improper synchronization mechanisms within the application's codebase, particularly in how it handles concurrent access to shared data structures during the authentication process.
The technical implementation of this vulnerability involves a race condition scenario where the Go runtime encounters unsynchronized access to a shared registeredStates map data structure. When multiple unauthorized users attempt to initiate OAuth2 login requests simultaneously, the application's internal map structure experiences concurrent writes without proper locking mechanisms. This concurrency issue triggers a fatal error in the Go runtime environment, specifically manifesting as "fatal error: concurrent map writes" which results in an immediate process termination. The root cause aligns with CWE-362, which describes a race condition vulnerability where two or more threads or processes access a shared resource concurrently, and at least one of them is a writer. This particular implementation violates proper concurrency control patterns that should be employed when managing shared mutable state in multi-threaded applications.
The operational impact of this vulnerability extends beyond simple service disruption, as it creates a vector for remote attackers to systematically crash the OliveTin service without requiring authentication credentials. The attack surface is particularly concerning because it affects the core authentication mechanism that is essential for the application's security posture. When OAuth2 is enabled, any remote attacker can exploit this weakness by flooding the /oauth/login endpoint with concurrent requests, leading to service unavailability for legitimate users and potentially disrupting critical system operations that depend on OliveTin's shell command execution capabilities. The vulnerability directly maps to ATT&CK technique T1499.004, which covers "Utilities: Endpoint Denial of Service," as it specifically targets endpoint availability through process termination rather than data corruption or network disruption.
Mitigation strategies for this vulnerability require immediate deployment of the patched version 3000.10.3 which implements proper synchronization mechanisms for the shared registeredStates map. Organizations should also consider implementing rate limiting measures at the network level to prevent abuse of the OAuth2 login endpoint, as well as monitoring for unusual patterns of concurrent requests that might indicate exploitation attempts. The fix addresses the underlying concurrency issue by ensuring that access to the shared map structure is properly synchronized through appropriate locking mechanisms, preventing the Go runtime from encountering the fatal concurrent map write error. Security teams should also review their OAuth2 configuration and consider disabling the feature if it is not actively required, as this removes the attack vector entirely. Additionally, implementing robust logging and alerting around authentication endpoints will help detect potential exploitation attempts and provide early warning of such attacks. The vulnerability serves as a reminder of the critical importance of proper concurrency control in multi-threaded applications and demonstrates how seemingly minor synchronization issues can result in severe operational impacts.