Information Disclosures

Overview of information disclosure vulnerabilities, their risks, and mitigations. This post serves as the entry point to categorized writeups on different forms of information leakage.

Description

Information disclosure vulnerabilities occur when an application, system, or service unintentionally exposes sensitive information to unauthorized users or attackers. This type of vulnerability poses a significant security risk as it allows adversaries to gain insights into the internal workings of an environment. An attacker exploiting this issue could access critical information such as internal IP addresses, email addresses, system details, or even credentials.

Once obtained, this information can be chained with other vulnerabilities to perform more targeted attacks—such as lateral movement, privilege escalation, or direct exploitation of exposed assets. In worst-case scenarios, information disclosure can lead directly to data breaches or compromise of business-critical systems.

Information Disclosure Is an Attack Multiplier

On its own, an information disclosure finding may seem low-severity. In reality, it often serves as a force multiplier, enabling attackers to make precise moves in later phases of an attack chain.

Remediation

Web Applications

Disable verbose error messages: Ensure production systems do not display stack traces or detailed error messages. Replace with generic error handling.
Suppress headers that reveal sensitive information: Remove or configure headers like Server, X-Powered-By, and X-AspNet-Version.
Implement proper access controls: Restrict access to confidential files, API endpoints, and database records.
Use Content Security Policy (CSP): Helps prevent unauthorized script execution and data leaks.
Sanitize and validate user input: Prevent unintended exposure of data via error messages or debug output.

Network and Protocol-Level Leaks

Disable unnecessary services and ports: Reduce attack surface by disabling outdated or unused protocols (e.g., Telnet, SMBv1).
Enforce encrypted communications: Use TLS 1.2+ for secure transmissions; disable weak SSL/TLS versions.
Configure SNMP securely: Use SNMPv3 with authentication and encryption; restrict SNMP access.
Disable ICMP timestamp responses: Prevent attackers from learning system uptime or internal time sources.

API and Application-Level Protections

Limit verbose responses from APIs: Ensure APIs do not return sensitive debug messages or internal identifiers.
Restrict unnecessary metadata exposure: Avoid exposing database IDs, email addresses, or system names in responses.
Use rate limiting: Prevent excessive requests that may reveal data patterns.

File and Directory Protections

Ensure proper permissions on sensitive files: Set restrictive permissions (e.g., avoid 777 on Linux or weak ACLs on Windows).
Disable directory listing: Configure web servers (Apache, Nginx, IIS) to prevent browsing of file directories.
Restrict access to log files: Protect logs containing sensitive data, error traces, or credentials.

Cloud and Database Security

Encrypt sensitive data at rest and in transit: Use AES-256 for storage and TLS for transmission.
Avoid storing secrets in code repositories: Use environment variables or secret management solutions (e.g., HashiCorp Vault, AWS Secrets Manager).
Properly configure cloud storage permissions: Keep S3 buckets, GCP Storage, or Azure Blobs private unless explicitly required.

References

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

Next Steps

This page serves as the overview for information disclosure vulnerabilities. Specific sub-pages will cover common cases in more detail, including:

Verbose error messages
Directory listing exposure
TLS/SSL information leakage
Cloud storage misconfigurations
Metadata service exposure

Explore these sub-sections to see real-world exploitation techniques, examples, and tailored remediations.

Information Disclosures

On this page