CVE-2018-12917 in PBC
Summary
by MITRE
In libpbc.a in PBC through 2017-03-02, there is a heap-based buffer over-read in _pbcM_ip_new in map.c.
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Analysis
by VulDB Data Team • 03/29/2023
The vulnerability identified as CVE-2018-12917 affects the PBC library version 2017-03-02 and earlier, specifically within the libpbc.a component. This issue manifests as a heap-based buffer over-read in the _pbcM_ip_new function located in the map.c file, representing a critical security flaw that can potentially compromise system integrity and availability. The PBC library, which stands for Pairing-Based Cryptography, is widely utilized in cryptographic implementations requiring bilinear pairings for various security protocols including identity-based encryption and short signatures.
The technical flaw stems from improper bounds checking within the _pbcM_ip_new function where the library fails to validate input parameters before processing them in memory operations. This buffer over-read condition occurs when the program attempts to read memory locations beyond the allocated buffer boundaries, potentially exposing sensitive data or causing unpredictable program behavior. The vulnerability is classified as a heap-based buffer over-read under CWE-125, which represents an out-of-bounds read condition where memory is accessed beyond the bounds of a heap-allocated buffer. This specific implementation flaw demonstrates poor memory management practices and inadequate input validation mechanisms that are fundamental requirements for secure software development.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can enable attackers to extract confidential information from adjacent memory locations, potentially including cryptographic keys, session data, or other sensitive parameters. In cryptographic contexts where PBC is employed, this over-read could compromise the security of entire cryptographic protocols by exposing critical information that adversaries might exploit for further attacks. The vulnerability is particularly concerning because it affects a core component used in cryptographic libraries that are integral to secure communications, authentication systems, and digital signature implementations. Attackers could leverage this flaw to perform information disclosure attacks or potentially manipulate the cryptographic operations to weaken the security posture of systems relying on affected PBC implementations.
Mitigation strategies for CVE-2018-12917 should prioritize immediate patching of the affected PBC library to version 2017-03-03 or later, which contains the necessary fixes for the buffer over-read condition. System administrators should conduct comprehensive vulnerability assessments to identify all instances of the vulnerable library across their infrastructure, particularly in environments utilizing cryptographic protocols that depend on PBC functionality. Additionally, implementing proper input validation and bounds checking mechanisms within applications using PBC libraries can provide defense-in-depth protection against similar vulnerabilities. Security monitoring should be enhanced to detect potential exploitation attempts through anomalous memory access patterns, and organizations should consider adopting memory safety tools and static analysis techniques to identify similar issues in their codebases. The vulnerability also aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as attackers might leverage such memory corruption vulnerabilities to execute arbitrary code or escalate privileges within compromised systems.
This vulnerability highlights the critical importance of proper memory management in cryptographic software, where even minor implementation flaws can have significant security implications. The issue demonstrates how buffer over-read vulnerabilities can compromise the confidentiality and integrity of cryptographic operations, emphasizing the need for rigorous code review processes and adherence to secure coding practices. Organizations should maintain updated threat intelligence on similar vulnerabilities in cryptographic libraries and ensure their security tooling can detect and prevent exploitation attempts targeting these fundamental software flaws.