CVE-2012-1568 in Red Hat
Summary
by MITRE
The ExecShield feature in a certain Red Hat patch for the Linux kernel in Red Hat Enterprise Linux (RHEL) 5 and 6 and Fedora 15 and 16 does not properly handle use of many shared libraries by a 32-bit executable file, which makes it easier for context-dependent attackers to bypass the ASLR protection mechanism by leveraging a predictable base address for one of these libraries.
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Analysis
by VulDB Data Team • 12/29/2021
The vulnerability described in CVE-2012-1568 represents a critical flaw in the implementation of kernel security features designed to protect against advanced exploitation techniques. This issue specifically affects Red Hat Enterprise Linux versions 5 and 6, as well as Fedora versions 15 and 16, where the ExecShield protection mechanism fails to properly manage memory layout for 32-bit executables that utilize multiple shared libraries. The flaw stems from improper handling of memory address allocation during program execution, creating predictable memory layouts that undermine fundamental security protections.
The technical implementation of ExecShield was intended to provide enhanced security through automatic stack and heap randomization, but the vulnerability demonstrates a significant gap in how the kernel manages shared library loading processes. When multiple shared libraries are loaded into memory by a 32-bit executable, the patch fails to randomize the base addresses of these libraries sufficiently, resulting in predictable memory layouts that attackers can exploit. This behavior directly violates the principles of address space layout randomization as outlined in the CWE-16 category, which specifically addresses weaknesses in the implementation of memory protection mechanisms.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it fundamentally weakens the security posture of affected systems by reducing the effectiveness of ASLR protections. Attackers can leverage this predictable memory layout to bypass security controls that would normally prevent successful exploitation of other vulnerabilities. This weakness creates a pathway for context-dependent attacks that could lead to complete system compromise, particularly when combined with other exploitation techniques. The vulnerability aligns with ATT&CK technique T1068 which describes the use of privilege escalation through exploitation of system vulnerabilities, and more specifically with T1059 which involves the execution of malicious code through system processes.
Mitigation strategies for CVE-2012-1568 require immediate system updates to patched kernel versions that properly implement ExecShield functionality. Organizations should ensure their systems are updated to the latest security patches provided by Red Hat, as these updates correct the flawed memory management behavior for shared library loading. Additionally, system administrators should implement monitoring for unusual memory access patterns and consider additional security controls such as mandatory access controls or extended protection mechanisms. The vulnerability highlights the importance of thorough testing of security patches in enterprise environments, as the flaw demonstrates how seemingly benign security features can introduce exploitable weaknesses when not properly implemented. Organizations should also review their overall security posture and consider implementing additional layers of protection beyond traditional ASLR mechanisms to maintain robust defense-in-depth strategies.