CVE-2016-2106 in Mac OS X
Summary
by MITRE
Integer overflow in the EVP_EncryptUpdate function in crypto/evp/evp_enc.c in OpenSSL before 1.0.1t and 1.0.2 before 1.0.2h allows remote attackers to cause a denial of service (heap memory corruption) via a large amount of data.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 09/06/2022
The vulnerability identified as CVE-2016-2106 represents a critical integer overflow flaw within the OpenSSL cryptographic library that affects versions prior to 1.0.1t and 1.0.2h. This issue resides in the EVP_EncryptUpdate function located in the crypto/evp/evp_enc.c source file, where improper handling of data size parameters creates conditions that can be exploited by remote attackers to compromise system stability. The vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, which occurs when an integer value exceeds its maximum representable value and wraps around to a smaller value, creating unexpected behavior in the program's execution flow.
The technical exploitation of this vulnerability involves sending a large amount of data to the affected OpenSSL implementation during encryption operations, specifically through the EVP_EncryptUpdate function. When the function processes this oversized data input, the integer overflow causes heap memory corruption, leading to unpredictable program behavior and potential system crashes. This memory corruption occurs because the function fails to properly validate or handle the size parameters of the data being encrypted, allowing malicious inputs to exceed the allocated memory boundaries and overwrite adjacent heap regions. The vulnerability is particularly dangerous because it can be triggered remotely without requiring authentication, making it an attractive target for denial of service attacks against systems relying on OpenSSL for secure communications.
From an operational perspective, this vulnerability poses significant risks to organizations that depend on OpenSSL for encryption services, including web servers, email servers, and any applications that utilize SSL/TLS protocols. The heap memory corruption resulting from the integer overflow can lead to complete system crashes, application instability, and potential data loss. Attackers can leverage this flaw to repeatedly cause service disruptions, effectively implementing a denial of service attack against target systems. The impact extends beyond simple service interruption as the memory corruption may also expose sensitive information or create conditions that could be exploited for more sophisticated attacks, particularly when combined with other vulnerabilities in the system. Organizations running vulnerable OpenSSL versions face potential reputational damage, operational downtime, and increased security risks.
The recommended mitigation strategy for CVE-2016-2106 involves immediate upgrading of OpenSSL installations to versions 1.0.1t or 1.0.2h and later, which contain the necessary patches to address the integer overflow condition. System administrators should also implement network monitoring to detect unusual traffic patterns that might indicate exploitation attempts, and consider deploying intrusion detection systems that can identify malicious data patterns targeting this specific vulnerability. Additionally, organizations should conduct comprehensive vulnerability assessments to identify all systems running affected OpenSSL versions and ensure proper patch management procedures are in place to prevent similar issues in the future. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for Network Denial of Service, emphasizing the need for proper input validation and memory management practices to prevent such exploits from compromising system integrity.