CVE-2017-7274 in radare2
Summary
by MITRE
The r_pkcs7_parse_cms function in libr/util/r_pkcs7.c in radare2 1.3.0 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted PE file.
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Analysis
by VulDB Data Team • 11/22/2022
The vulnerability identified as CVE-2017-7274 resides within the radare2 binary analysis framework, specifically in the r_pkcs7_parse_cms function located in libr/util/r_pkcs7.c at version 1.3.0. This flaw represents a classic null pointer dereference issue that can be exploited by remote attackers to disrupt the normal operation of the application. The vulnerability manifests when the application processes crafted PE files that contain malformed PKCS#7 CMS (Cryptographic Message Syntax) structures, leading to a crash that results in denial of service. The affected component is part of radare2's utility library, which handles various cryptographic operations and file format parsing tasks essential for binary analysis activities. This function is designed to parse PKCS#7 CMS structures commonly found in digital signatures and encrypted content within executable files, making it a critical component for processing PE files that may contain cryptographic metadata.
The technical implementation of this vulnerability stems from inadequate input validation within the r_pkcs7_parse_cms function, which fails to properly handle malformed or unexpected data structures during PKCS#7 CMS parsing operations. When a crafted PE file containing maliciously constructed PKCS#7 CMS data is processed, the function attempts to dereference a null pointer that should have been validated or initialized before use. This particular flaw aligns with CWE-476, which categorizes null pointer dereference conditions as a common class of software vulnerabilities that can lead to application crashes and potential exploitation. The vulnerability is particularly concerning because it can be triggered remotely through the processing of untrusted PE files, making it accessible to attackers who can induce the target system to parse malicious content. The lack of proper error handling and validation in the cryptographic parsing routine creates a direct path for attackers to cause the application to crash by simply presenting it with specially crafted input data.
The operational impact of CVE-2017-7274 extends beyond simple application instability, as it represents a significant denial of service threat that can disrupt security analysis workflows and binary examination processes. Organizations that rely on radare2 for malware analysis, reverse engineering, or security research operations may find their analytical capabilities compromised when encountering malicious PE files that trigger this vulnerability. The crash occurs during normal file processing operations, meaning that legitimate security analysts could inadvertently trigger the vulnerability while examining suspicious files, leading to operational disruptions and potential loss of analysis progress. This vulnerability is particularly dangerous in automated analysis environments where systems process large volumes of potentially malicious files, as a single crafted PE file could cause cascading failures across multiple analysis tasks. The vulnerability also represents a potential vector for more sophisticated attacks, as the crash behavior could be leveraged to create conditions for further exploitation or to mask malicious activities by disrupting normal system operations.
Mitigation strategies for CVE-2017-7274 should focus on immediate software updates and defensive programming practices. The most effective remediation involves upgrading to radare2 version 2.0.0 or later, where the vulnerability has been addressed through improved input validation and null pointer checks within the r_pkcs7_parse_cms function. Organizations should implement defensive measures such as validating input files before processing them in security analysis environments, particularly when dealing with PE files from untrusted sources. Network-based defenses can include implementing file type filtering and sandboxing mechanisms that prevent potentially malicious PE files from reaching systems running radare2. Additionally, system administrators should consider implementing monitoring solutions that can detect application crashes and automatically restart services to minimize disruption. The vulnerability demonstrates the importance of proper error handling in cryptographic processing components and aligns with ATT&CK technique T1059, which covers the use of system services and utilities for execution and persistence. Organizations should also consider implementing principle of least privilege access controls for security analysis tools and regularly review their threat modeling to account for potential exploitation vectors in binary analysis frameworks.