CVE-2018-25049 in email-existence
Summary
by MITRE • 12/27/2022
A vulnerability was found in email-existence. It has been rated as problematic. Affected by this issue is some unknown functionality of the file index.js. The manipulation leads to inefficient regular expression complexity. The name of the patch is 0029ba71b6ad0d8ec0baa2ecc6256d038bdd9b56. It is recommended to apply a patch to fix this issue. VDB-216854 is the identifier assigned to this vulnerability.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/24/2023
The vulnerability identified as CVE-2018-25049 represents a significant security flaw within the email-existence library that affects the index.js file implementation. This issue manifests as inefficient regular expression complexity that can be exploited through specific manipulation patterns, creating a potential denial of service vector that impacts the overall system stability and performance. The vulnerability stems from improper handling of regular expression patterns within the email validation functionality, where malicious input can cause exponential backtracking in the regex engine, leading to resource exhaustion and system instability.
The technical flaw resides in the regular expression implementation within the email-existence library's index.js file, where the regex patterns are not properly optimized to handle adversarial input sequences. This vulnerability directly maps to CWE-1333 which describes inefficient regular expression complexity, specifically when regular expressions are susceptible to catastrophic backtracking scenarios. The problematic implementation allows attackers to craft input strings that cause the regular expression engine to perform an excessive number of operations, potentially leading to complete system resource exhaustion and denial of service conditions.
From an operational perspective, this vulnerability poses a substantial risk to systems that rely on email validation services, particularly those processing user input or batch email verification operations. The impact extends beyond simple service disruption to potentially affect system availability and performance across multiple applications that depend on the vulnerable library. Attackers can exploit this weakness by submitting carefully crafted email addresses that trigger the inefficient regex patterns, causing the system to consume excessive CPU cycles and memory resources. This behavior aligns with ATT&CK technique T1499.004 which involves resource exhaustion via malicious input manipulation.
The recommended mitigation involves applying the specific patch identified by the commit hash 0029ba71b6ad0d8ec0baa2ecc6256d038bdd9b56, which addresses the inefficient regular expression complexity by either optimizing the existing patterns or implementing alternative validation approaches. Organizations should also consider implementing input validation measures, rate limiting for email validation endpoints, and monitoring for unusual resource consumption patterns that might indicate exploitation attempts. Additionally, upgrading to newer versions of the email-existence library that have addressed this vulnerability is crucial for maintaining system security posture and preventing potential exploitation scenarios that could lead to broader system compromise.