GHSA-CR4G-F395-H25H

Vulnerability from github – Published: 2026-06-16 23:42 – Updated: 2026-06-16 23:42
VLAI
Summary
Gitea: Token scope bypass on web archive download endpoint
Details

Summary

PR #37698 added checkDownloadTokenScope to /raw/, /media/, and attachment download web endpoints. The /archive/* endpoint (repo.Download in routers/web/repo/repo.go:372) was not included in the fix. This endpoint accepts OAuth2 tokens via webAuth.AllowOAuth2 (registered at routers/web/web.go:1649-1652) but does not call checkDownloadTokenScope or CheckRepoScopedToken.

A personal access token with any non-repository scope (e.g., read:issue or read:misc) can download full repository archives (zip/tar.gz) of private repositories the token owner has access to.

Impact

Scope escalation: tokens scoped to non-repository categories can access full repository content through the archive download endpoint. Higher impact than endpoints fixed in #37698 because /archive/* serves the entire repository.

Steps to Reproduce

  1. Create a personal access token with ONLY read:misc scope
  2. Access: GET /{owner}/{private-repo}/archive/main.tar.gz
  3. Archive is served (200 OK) instead of being rejected (403 Forbidden)

Compare with fixed endpoints: - GET /{owner}/{private-repo}/raw/branch/main/README.md correctly returns 403

Root Cause

Download function in routers/web/repo/repo.go:372 does not call checkDownloadTokenScope. The outer group middleware reqUnitCodeReader checks repository permission but not token scope.

The API equivalent (/api/v1/repos/{owner}/{repo}/archive/*) IS properly scoped via tokenRequiresScopes(AccessTokenScopeCategoryRepository). The git HTTP endpoints are scoped via CheckRepoScopedToken in httpBase.

Suggested Fix

Add checkDownloadTokenScope(ctx) to Download and InitiateDownload in routers/web/repo/repo.go. The function already exists in routers/web/repo/download.go (same package).

Discovery Method

Variant analysis of PR #37698 — reviewed all web routes with webAuth.AllowOAuth2 middleware.

Show details on source website

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.26.1"
      },
      "package": {
        "ecosystem": "Go",
        "name": "code.gitea.io/gitea"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.26.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-20706"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-16T23:42:04Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nPR #37698 added checkDownloadTokenScope to /raw/*, /media/*, and attachment download web endpoints. The /archive/* endpoint (repo.Download in routers/web/repo/repo.go:372) was not included in the fix. This endpoint accepts OAuth2 tokens via webAuth.AllowOAuth2 (registered at routers/web/web.go:1649-1652) but does not call checkDownloadTokenScope or CheckRepoScopedToken.\n\nA personal access token with any non-repository scope (e.g., read:issue or read:misc) can download full repository archives (zip/tar.gz) of private repositories the token owner has access to.\n\n## Impact\n\nScope escalation: tokens scoped to non-repository categories can access full repository content through the archive download endpoint. Higher impact than endpoints fixed in #37698 because /archive/* serves the entire repository.\n\n## Steps to Reproduce\n\n1. Create a personal access token with ONLY read:misc scope\n2. Access: GET /{owner}/{private-repo}/archive/main.tar.gz\n3. Archive is served (200 OK) instead of being rejected (403 Forbidden)\n\nCompare with fixed endpoints:\n- GET /{owner}/{private-repo}/raw/branch/main/README.md correctly returns 403\n\n## Root Cause\n\nDownload function in routers/web/repo/repo.go:372 does not call checkDownloadTokenScope. The outer group middleware reqUnitCodeReader checks repository permission but not token scope.\n\nThe API equivalent (/api/v1/repos/{owner}/{repo}/archive/*) IS properly scoped via tokenRequiresScopes(AccessTokenScopeCategoryRepository). The git HTTP endpoints are scoped via CheckRepoScopedToken in httpBase.\n\n## Suggested Fix\n\nAdd checkDownloadTokenScope(ctx) to Download and InitiateDownload in routers/web/repo/repo.go. The function already exists in routers/web/repo/download.go (same package).\n\n## Discovery Method\n\nVariant analysis of PR #37698 \u2014 reviewed all web routes with webAuth.AllowOAuth2 middleware.",
  "id": "GHSA-cr4g-f395-h25h",
  "modified": "2026-06-16T23:42:04Z",
  "published": "2026-06-16T23:42:04Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/go-gitea/gitea/security/advisories/GHSA-cr4g-f395-h25h"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/go-gitea/gitea"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Gitea: Token scope bypass on web archive download endpoint"
}



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