CVE-2010-3717 in TYPO3
Summary
by MITRE
The t3lib_div::validEmail function in TYPO3 4.2.x before 4.2.15, 4.3.x before 4.3.7, and 4.4.x before 4.4.4 does not properly restrict input to filter_var FILTER_VALIDATE_EMAIL operations in PHP, which allows remote attackers to cause a denial of service (memory consumption and application crash) via a long e-mail address string, a related issue to CVE-2010-3710.
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Analysis
by VulDB Data Team • 09/28/2021
The vulnerability identified as CVE-2010-3717 affects TYPO3 content management systems across multiple version ranges including 4.2.x before 4.2.15, 4.3.x before 4.3.7, and 4.4.x before 4.4.4. This issue resides within the t3lib_div::validEmail function which is responsible for email address validation within the TYPO3 framework. The flaw stems from inadequate input sanitization when processing email addresses through PHP's filter_var function with FILTER_VALIDATE_EMAIL flag, creating a potential avenue for malicious exploitation.
The technical implementation of this vulnerability exploits the inherent behavior of PHP's filter_var function when processing excessively long email address strings. When the t3lib_div::validEmail function processes malformed or overly lengthy email addresses, the underlying filter_var operation consumes disproportionate system resources. This occurs because PHP's email validation mechanism becomes computationally intensive when processing strings that exceed normal email address length parameters, leading to exponential resource consumption patterns that can exhaust available memory and cause application instability.
From an operational perspective, this vulnerability presents a significant denial of service risk that can be exploited by remote attackers without requiring authentication or privileged access. The attack vector involves sending specially crafted email address strings to TYPO3 applications that utilize the vulnerable validation function, resulting in memory exhaustion and potential application crashes. This affects not only the targeted web application but can also impact overall system stability and availability, particularly in environments where multiple users might interact with email validation features.
The vulnerability aligns with CWE-770, which addresses allocation of resources without reasonable limits, and demonstrates characteristics consistent with the ATT&CK technique T1499.004 for Network Denial of Service. Organizations running affected TYPO3 versions face potential business disruption and service degradation, as attackers can systematically consume system resources through repeated submissions of long email address strings. The impact extends beyond simple application crashes to include potential cascading failures in web server performance and user experience degradation.
Mitigation strategies should prioritize immediate patching of affected TYPO3 installations to versions 4.2.15, 4.3.7, and 4.4.4 respectively, which contain the necessary fixes for the email validation function. Additionally, implementing input length validation and rate limiting mechanisms at network boundaries can provide defense-in-depth measures. System administrators should also consider implementing monitoring for unusual resource consumption patterns and establish automated alerting for potential exploitation attempts. Organizations should conduct comprehensive vulnerability assessments to identify all instances of affected TYPO3 installations and ensure proper configuration of PHP's filter_var operations with appropriate input validation limits.