CVE-2015-3797

Vulnerability

The vulnerability resides in the TRE regular expression library within Libc in Apple iOS (before 8.4.1) and OS X (before 10.10.5). Processing a crafted regular expression can cause memory corruption in the regex engine, leading to arbitrary code execution or application crash [1][2].

Exploitation

A context-dependent attacker can exploit this vulnerability by providing a malicious regular expression to an application that uses the TRE library. No authentication is required, but the attacker must be able to submit the crafted regex (e.g., via a web page, email, or network service) to trigger the memory corruption.

Impact

Successful exploitation allows the attacker to execute arbitrary code with the privileges of the affected application or cause a denial of service through memory corruption and application crash. The impact includes full compromise of the application and potential escalation depending on the process's privileges.

Mitigation

Apple addressed this vulnerability in iOS 8.4.1 and OS X Yosemite 10.10.5 and Security Update 2015-006, as documented in the security advisory pages [1][2]. Users should update their devices to the latest available operating system versions. No workarounds are publicly disclosed.