Public disclosure of vulnerabilities is an essential aspect of maintaining cybersecurity, but not all vulnerabilities are treated equally in terms of their impact and the necessity for public disclosure. Generally, vulnerabilities considered to be low-impact are excluded from the scope of public disclosure for several reasons. Firstly, these vulnerabilities typically pose minimal risk to the security posture of an organization or its users, meaning they are unlikely to be exploited in a way that would cause significant harm. Secondly, the exploitation of these vulnerabilities often requires highly unlikely or specific conditions, making them impractical for malicious actors to leverage effectively. As a result, the resources required to address these issues might outweigh the potential benefits, particularly when weighed against the need to focus on higher-impact vulnerabilities that could lead to more severe consequences.
Another reason for excluding low-impact vulnerabilities from public disclosure is the potential for creating unnecessary noise. When too many minor issues are reported, it can dilute the attention of security teams, causing them to focus on less critical concerns rather than prioritizing and addressing vulnerabilities that pose a real threat. Additionally, disclosing minor vulnerabilities can lead to a false sense of security or even cause undue alarm among users and stakeholders, who might misunderstand the true risk associated with these issues. By setting a threshold for public disclosure, organizations can ensure that only vulnerabilities with significant potential impact are communicated, thus maintaining a more effective and focused security response.
Types of Low Impact Vulnerabilities Often Out of Scope:
- Enumeration and Session Management:
- Account/email enumeration using brute-force attacks.
- Any low-impact issues related to session management, such as concurrent sessions, session expiration, or password reset/logout procedures.
- Content and UI Issues:
- Clickjacking or UI redressing.
- Reflected file download attacks (RFD).
- URL/Open Redirection.
- Information Disclosure and Configuration Issues:
- Descriptive or verbose error pages without proof of exploitability.
- Directory structure enumeration unless it reveals exceptionally useful information.
- Missing or improperly configured SPF/DMARC/DKIM records.
- Low impact information disclosures, including software version disclosure.
- Issues related to missing cookie flags or HTTP headers/methods that do not lead directly to a security vulnerability.
- Encryption and Security Best Practices:
- Lack of SSL or mixed content that doesn’t involve leaking sensitive data.
- SSL/TLS best practices that lack a fully functional proof of concept.
- Use of known-vulnerable libraries leading to low-impact vulnerabilities, like outdated jQuery causing low-impact XSS.
In addition to the commonly out-of-scope vulnerabilities, certain specific types of vulnerabilities are also considered too low-impact to warrant public disclosure. These vulnerabilities typically involve configurations or issues that, while technically present, do not pose a significant risk or are unlikely to be exploited in a meaningful way. For example, IIS Tilde File and Directory Disclosure and SSH Username Enumeration reveal information that is generally not sensitive or critical. Similarly, WordPress Username Enumeration and SSL Weak Ciphers/POODLE/Heartbleed are often categorized as low-impact because they either provide non-sensitive information or require very specific conditions to be exploited.
Additional vulnerabilities include CSV Injection and PHP Info disclosures, which might expose minor configuration details without offering a direct pathway to exploitation. Server-Status disclosures are also typically out of scope unless they reveal sensitive information. Finally, Snoop Info Disclosures are considered low-risk because they do not typically result in access to critical data or functionalities. These vulnerabilities are generally excluded from public disclosure to avoid overloading security teams with low-priority issues and to focus attention on more significant threats.
By excluding these low-impact vulnerabilities from public disclosure, organizations can focus their efforts on mitigating risks that pose a more significant threat to their security posture. This prioritization helps maintain the integrity of the security process, ensuring that resources are allocated efficiently and that the most critical vulnerabilities are addressed in a timely manner. Moreover, this approach aligns with industry standards, which advocate for a balanced and risk-based approach to vulnerability management.