CVE-2015-3145 in cURL
Summary
by MITRE
The sanitize_cookie_path function in cURL and libcurl 7.31.0 through 7.41.0 does not properly calculate an index, which allows remote attackers to cause a denial of service (out-of-bounds write and crash) or possibly have other unspecified impact via a cookie path containing only a double-quote character.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/09/2022
The vulnerability identified as CVE-2015-3145 affects cURL and libcurl versions ranging from 7.31.0 through 7.41.0, representing a critical out-of-bounds write condition that can lead to denial of service or potentially more severe consequences. This flaw resides within the sanitize_cookie_path function, which is responsible for processing cookie path information during HTTP communication. The issue manifests when the function encounters a cookie path containing exclusively a double-quote character, creating a scenario where the index calculation becomes malformed and leads to memory corruption.
The technical root cause of this vulnerability stems from improper bounds checking within the cookie path sanitization logic. When cURL processes a cookie path that consists solely of a double-quote character, the function fails to correctly handle the edge case, resulting in an index calculation that exceeds the allocated memory boundaries. This out-of-bounds write condition occurs because the implementation does not adequately validate the input length or properly handle special characters within cookie path strings. The vulnerability aligns with CWE-129, which addresses improper validation of array indices, and represents a classic example of unchecked buffer access that can be exploited through malformed input data.
The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially allow remote attackers to execute arbitrary code or cause system instability. An attacker could craft a malicious HTTP response containing a specially formatted cookie path with only a double-quote character, which when processed by the vulnerable cURL library would trigger the out-of-bounds write. This could result in application crashes, system instability, or in more severe cases, provide a potential pathway for privilege escalation or remote code execution depending on the execution environment. The vulnerability affects any system that relies on cURL or libcurl for HTTP communication and could be particularly dangerous in server environments where these libraries are extensively used for web scraping, API integration, or automated processes.
Mitigation strategies for CVE-2015-3145 primarily focus on immediate version updates to cURL or libcurl 7.42.0 or later, where the vulnerability has been addressed through proper index calculation and bounds checking. Organizations should conduct comprehensive inventory assessments to identify all systems utilizing vulnerable versions of these libraries and prioritize patching across all affected environments. Additionally, network monitoring should be enhanced to detect potentially malicious cookie values that might exploit this vulnerability, though such detection would be challenging since the attack vector involves legitimate HTTP communication patterns. System administrators should also consider implementing input validation controls at the network level, though this approach is less effective than proper library updates. The fix implemented in subsequent versions demonstrates the importance of proper array boundary validation and input sanitization, aligning with ATT&CK technique T1070.004 for indicator removal and T1211 for exploitation for defense evasion, as attackers might attempt to use such vulnerabilities to establish persistent access or hide malicious activities through corrupted system components.