CVE-2024-21631 Explained : Impact and Mitigation

This CVE-2024-21631 involves an integer overflow vulnerability in the URI of the Vapor HTTP web framework for Swift, specifically affecting versions prior to 4.90.0. The vulnerability could potentially lead to host spoofing, posing a security risk to applications using the affected versions of Vapor.

Understanding CVE-2024-21631

This vulnerability arises from improper input validation within the Vapor framework, which may allow malicious actors to exploit integer overflows when parsing untrusted inputs. By manipulating certain properties within the URI type, attackers could deceive applications into accepting URLs pointing to untrusted destinations, potentially leading to host spoofing.

What is CVE-2024-21631?

The CVE-2024-21631 vulnerability in Vapor stems from the improper use of

uint16_t

indexes in the

vapor_urlparser_parse

function, leading to integer overflows during URI component parsing. While Vapor itself remains unaffected, applications relying on URI for user input validation may be at risk. This vulnerability underscores the importance of thorough input validation to prevent security breaches.

The Impact of CVE-2024-21631

The impact of CVE-2024-21631 lies in the potential for host spoofing, where attackers could manipulate URLs to bypass security measures by exploiting integer overflows in URI parsing. This could compromise the integrity of applications and expose them to various security threats if left unaddressed.

Technical Details of CVE-2024-21631

The vulnerability description revolves around the misuse of

uint16_t

indexes in URI parsing, leading to integer overflows during input validation. The affected systems are those running versions of Vapor prior to 4.90.0, where the

vapor_urlparser_parse

function is susceptible to exploitation.

Vulnerability Description

The vulnerability in CVE-2024-21631 arises from the incorrect handling of URI components using 16-bit integers, allowing attackers to trigger integer overflows by manipulating certain properties. This could potentially lead to host spoofing and compromise the security of applications relying on these components.

Affected Systems and Versions

Systems running versions of Vapor below 4.90.0 are affected by CVE-2024-21631. The vulnerability specifically targets the

vapor_urlparser_parse

function, putting applications at risk if proper mitigation measures are not implemented.

Exploitation Mechanism

Attackers can exploit CVE-2024-21631 by manipulating untrusted inputs within URI components, triggering integer overflows during parsing. By manipulating URLs and padding port numbers with zeros, malicious actors can deceive applications into accepting URLs pointing to malicious hosts, potentially leading to host spoofing.

Mitigation and Prevention

To address CVE-2024-21631 and prevent host spoofing attacks, immediate steps are recommended along with long-term security practices to enhance the overall resilience of applications running vulnerable versions of Vapor.

Immediate Steps to Take

Developers should validate user input rigorously before parsing it as a URI, especially in applications relying on Vapor versions below 4.90.0. Implementing input validation checks can help mitigate the risk of exploitation and prevent potential security breaches.

Long-Term Security Practices

In the long term, adopting secure coding practices, conducting regular security audits, and staying informed about framework updates can help bolster the overall security posture of applications. Educating developers on secure coding techniques and emphasizing the importance of input validation can reduce the likelihood of similar vulnerabilities in the future.

Patching and Updates

For immediate mitigation of CVE-2024-21631, it is crucial to update affected systems to Vapor version 4.90.0 or higher, which contains a patch for the identified vulnerability. Additionally, utilizing Foundation's

URL

and

URLComponents

utilities as alternatives to URI parsing in critical applications can enhance security and prevent potential exploit risks.