GHSA-45M3-398W-M2M9

Vulnerability from github – Published: 2026-03-02 21:41 – Updated: 2026-03-05 22:49
VLAI?
Summary
OliveTin has unauthenticated DoS via concurrent map writes in OAuth2 state handling
Details

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

  1. Start OliveTin with OAuth2 provider configured (example github), exposing port 1337.
  2. 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.

  1. 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
  1. 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.

poc_oauth2_state_map_race_dos.py

Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/OliveTin/OliveTin"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.0.0-20260301235225-f044d90d5525c"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-28789"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-362",
      "CWE-400",
      "CWE-662"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-02T21:41:36Z",
    "nvd_published_at": "2026-03-05T20:16:16Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nAn unauthenticated denial-of-service vulnerability exists in OliveTin\u2019s OAuth2 login flow. Concurrent requests to /oauth/login can trigger unsynchronized access to a shared registeredStates map, causing a Go runtime panic (fatal\n  error: concurrent map writes) and process termination. This allows remote attackers to crash the service when OAuth2 is enabled.\n\n\n### Details\nThe OAuth2 handler stores per-login state in a shared map without synchronization:\n\n  - service/internal/auth/otoauth2/restapi_auth_oauth2.go:24\n    registeredStates map[string]*oauth2State\n  - Unlocked write in login handler: .../restapi_auth_oauth2.go:141\n  - Unlocked read in callback check: .../restapi_auth_oauth2.go:174\n  - Unlocked writes in callback flow: .../restapi_auth_oauth2.go:284-285\n  - Unlocked read in auth chain check: .../restapi_auth_oauth2.go:376\n\n  These paths are network reachable via publicly registered routes:\n```bash\n  - service/internal/httpservers/frontend.go:71 \u2192 /oauth/login\n  - service/internal/httpservers/frontend.go:72 \u2192 /oauth/callback\n```\n  Because Go HTTP handlers run concurrently, high parallel traffic to /oauth/login causes concurrent map access and runtime panic.\n\n  Tested on:\n\n  - Container image: ghcr.io/olivetin/olivetin:3000.10.0\n  - Source also contains same pattern at commit/tag eb42029b5d0c0633551621288180dd4566b913f7 (3000.10.1)\n\n\n### PoC\n1. Start OliveTin with OAuth2 provider configured (example github), exposing port 1337.\n  2. Confirm baseline:\n```bash\n  curl -i http://127.0.0.1:1337/readyz\n  curl -i \"http://127.0.0.1:1337/oauth/login?provider=github\"\n```\n  Expected: 200 for /readyz, 302 for /oauth/login.\n\n  3. Run concurrency PoC:\n```bash\n  python3 /OliveTin/tools/poc_oauth2_state_map_race_dos.py \\\n    --base-url http://127.0.0.1:1337 \\\n    --provider github \\\n    --workers 80 \\\n    --requests 120000 \\\n    --health-failures 3\n```\n  4. Verify crash:\n\n  docker inspect olivetin-dos --format \u0027status={{.State.Status}} exit={{.State.ExitCode}}\u0027\n  docker logs olivetin-dos 2\u003e\u00261 | grep -E \"fatal error: concurrent map|concurrent map writes|restapi_auth_oauth2.go\"\n\n  Observed result:\n\n  - Process exited with code 2\n  - Logs include:\n      - fatal error: concurrent map writes\n      - .../internal/auth/otoauth2/restapi_auth_oauth2.go:141 in HandleOAuthLogin\n\n\n\n### Impact\n- Vulnerability type: Race condition (CWE-362) leading to DoS.\n  - Attacker requirements: network access only; no authentication required for exploit path.\n  - Impacted deployments: OliveTin instances with OAuth2 enabled and reachable over network.\n  - Security impact: remote unauthenticated attacker can repeatedly crash OliveTin, causing availability loss until restart/recovery.\n \n[poc_oauth2_state_map_race_dos.py](https://github.com/user-attachments/files/25577901/poc_oauth2_state_map_race_dos.py)",
  "id": "GHSA-45m3-398w-m2m9",
  "modified": "2026-03-05T22:49:34Z",
  "published": "2026-03-02T21:41:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/OliveTin/OliveTin/security/advisories/GHSA-45m3-398w-m2m9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28789"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OliveTin/OliveTin/commit/f044d90d5525c4c8e3f421b32ed7eff771c22d36"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/OliveTin/OliveTin"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OliveTin has unauthenticated DoS via concurrent map writes in OAuth2 state handling"
}


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