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GHSA-45m3-398w-m2m9
No affected components available
Summary
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.
Details
The OAuth2 handler stores per-login state in a shared map without synchronization:
- service/internal/auth/otoauth2/restapi_auth_oauth2.go:24 registeredStates map[string]*oauth2State
- Unlocked write in login handler: .../restapi_auth_oauth2.go:141
- Unlocked read in callback check: .../restapi_auth_oauth2.go:174
- Unlocked writes in callback flow: .../restapi_auth_oauth2.go:284-285
- Unlocked read in auth chain check: .../restapi_auth_oauth2.go:376
These paths are network reachable via publicly registered routes:
- service/internal/httpservers/frontend.go:71 → /oauth/login
- service/internal/httpservers/frontend.go:72 → /oauth/callback
Because Go HTTP handlers run concurrently, high parallel traffic to /oauth/login causes concurrent map access and runtime panic.
Tested on:
- Container image: ghcr.io/olivetin/olivetin:3000.10.0
- Source also contains same pattern at commit/tag eb42029b5d0c0633551621288180dd4566b913f7 (3000.10.1)
PoC
- Start OliveTin with OAuth2 provider configured (example github), exposing port 1337.
- Confirm baseline:
curl -i http://127.0.0.1:1337/readyz
curl -i "http://127.0.0.1:1337/oauth/login?provider=github"
Expected: 200 for /readyz, 302 for /oauth/login.
- Run concurrency PoC:
python3 /OliveTin/tools/poc_oauth2_state_map_race_dos.py \
--base-url http://127.0.0.1:1337 \
--provider github \
--workers 80 \
--requests 120000 \
--health-failures 3
- Verify crash:
docker inspect olivetin-dos --format 'status={{.State.Status}} exit={{.State.ExitCode}}' docker logs olivetin-dos 2>&1 | grep -E "fatal error: concurrent map|concurrent map writes|restapi_auth_oauth2.go"
Observed result:
- Process exited with code 2
- Logs include:
- fatal error: concurrent map writes
- .../internal/auth/otoauth2/restapi_auth_oauth2.go:141 in HandleOAuthLogin
Impact
- Vulnerability type: Race condition (CWE-362) leading to DoS.
- Attacker requirements: network access only; no authentication required for exploit path.
- Impacted deployments: OliveTin instances with OAuth2 enabled and reachable over network.
- Security impact: remote unauthenticated attacker can repeatedly crash OliveTin, causing availability loss until restart/recovery.
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the availability of the system.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
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