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Telegram Bot Token

A Telegram Bot Token is a unique identifier used to authenticate and interact with the Telegram Bot API. This token allows developers to send messages, manage groups, and perform various actions through their bots. Exposure of this token is a significant security concern because it grants full control over the bot, enabling unauthorized users to send messages, access chat history, and potentially manipulate bot behavior.

How Does It Look​

Telegram Bot Tokens can appear in various contexts, such as:

  • Environment variables:

    export TELEGRAM_BOT_TOKEN="123456789:ABCdefGhIJKlmnoPQRstuVWXyz"

  • Configuration files (JSON, YAML, .env):

    {
      "telegram": {
        "bot_token": "123456789:ABCdefGhIJKlmnoPQRstuVWXyz"
      }
    }

  • Code snippets:

    bot = telegram.Bot(token="123456789:ABCdefGhIJKlmnoPQRstuVWXyz")

  • Connection strings (if applicable):

    telegram://bot123456789:ABCdefGhIJKlmnoPQRstuVWXyz@telegram.org

Severity​

  • 🔴 Critical

The severity is critical because the bot token provides full access to the bot's capabilities. An attacker with this token can impersonate the bot, send unauthorized messages, and access sensitive chat data. The blast radius includes all users and groups the bot interacts with, potentially leading to widespread misinformation or data breaches.

What Can an Attacker Do?​

With immediate access to a Telegram Bot Token, an attacker can fully control the bot's actions and interactions.

Key actions an attacker can perform:

  • Send unauthorized messages: Impersonate the bot to send misleading or harmful messages to users and groups (if the bot has messaging permissions).
  • Access chat history: Retrieve sensitive information from conversations (if the bot has access to chat data).
  • Modify bot settings: Change bot configurations or commands (if the bot allows configuration changes).
  • Add or remove users from groups: Manipulate group memberships (if the bot has administrative privileges).

An attacker could also escalate their access by using the bot to gather more information about users or groups, potentially leading to further exploitation or lateral movement within the Telegram ecosystem.

Real-World Impact​

Exposure of a Telegram Bot Token poses significant business risks, including:

Primary impact includes unauthorized control over bot activities.

Potential consequences include:

  • Data Exposure: Access to sensitive chat data and user information (if the bot has read access to conversations).
  • Financial Loss: Potential for fraudulent activities or scams conducted through the bot (if the bot is used for transactions).
  • Operational Disruption: Interruption of legitimate bot services, affecting user experience (if the attacker modifies or disables bot functions).
  • Reputational Damage: Loss of trust from users and partners due to unauthorized bot activities.

In a worst-case scenario, the attacker could use the bot to spread misinformation or conduct phishing attacks, leading to cascading effects across the platform.

Prerequisites for Exploitation​

To exploit a Telegram Bot Token, an attacker needs:

  • Network access: Ability to connect to the Telegram API.
  • Bot token: The exposed token itself.
  • Additional context: Knowledge of the bot's intended functions and user base.

How to Verify If It's Active​

To verify if a Telegram Bot Token is active, use the following command:

curl -s -X GET "https://api.telegram.org/bot[TOKEN]/getMe"

Valid credential response: A JSON response with bot details, such as username and ID.

Invalid/expired credential response: An error message indicating invalid token or unauthorized access.

Detection Patterns​

Common Variable Names:

  • TELEGRAM_BOT_TOKEN
  • BOT_TOKEN
  • TELEGRAM_TOKEN
  • TG_BOT_TOKEN
  • TELEGRAM_API_TOKEN
  • BOT_API_KEY

File Locations:

  • .env
  • config.json
  • settings.yaml
  • bot_config.py
  • telegram_config.js

Regex Pattern:

\b\d{9}:[A-Za-z0-9_-]{35}\b

Remediation Steps​

  1. Revoke immediately - Go to the Telegram BotFather and regenerate the bot token to invalidate the exposed one.
  2. Audit access logs - Review Telegram bot activity logs for unauthorized messages or actions during the exposure window.
  3. Assess blast radius - Identify all users, groups, and systems that interacted with the exposed bot token.
  4. Rotate credential - Generate a new bot token using BotFather and update it in all relevant systems.
  5. Update dependent systems - Deploy the new token to all applications and update CI/CD pipelines securely.
  6. Harden access controls - Limit bot permissions to the minimum necessary and enable two-factor authentication for the bot owner account.
  7. Implement secrets management - Migrate bot tokens to a secrets manager (HashiCorp Vault, AWS Secrets Manager) to prevent hardcoding.
  8. Add detection controls - Set up pre-commit hooks and repository scanning to catch credential leaks before they reach production.

Credential exposures often go undetected for extended periods, increasing the window for exploitation. As a long-term strategy, plan to establish an internal process or engage an external vendor for continuous external exposure monitoring. This helps identify leaked secrets across public repositories, paste sites, dark web forums, and other external sources before attackers can leverage them. Proactive detection and rapid response are essential to minimizing the impact of credential leaks.

References​