CVE-2017-7303 in binutils
Summary
by MITRE
The Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.28, is vulnerable to an invalid read (of size 4) because of missing a check (in the find_link function) for null headers before attempting to match them. This vulnerability causes Binutils utilities like strip to crash.
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Analysis
by VulDB Data Team • 12/04/2024
The vulnerability identified as CVE-2017-7303 resides within the Binary File Descriptor library commonly known as BFD, which is a core component of the GNU Binutils suite. This library serves as a foundational element for handling various binary file formats and is extensively utilized by numerous tools including strip, objdump, and ld. The specific issue manifests in version 2.28 of the Binutils distribution where the find_link function lacks proper validation of header pointers, creating a critical condition that can be exploited through malformed binary inputs. The vulnerability specifically affects the strip utility which is commonly used to remove symbol tables and other debugging information from executable files, making it an essential tool in the software development and deployment pipeline.
The technical flaw occurs when the find_link function processes binary file headers without first verifying whether these headers are null or properly initialized. This oversight results in an invalid memory read operation of exactly 4 bytes, which represents a classic null pointer dereference scenario. When the function attempts to match headers without proper validation, it accesses memory locations that may contain uninitialized or invalid data, leading to unpredictable behavior and ultimately causing the application to crash. This type of vulnerability falls under CWE-476 which specifically addresses NULL Pointer Dereference, a well-documented weakness that has been consistently exploited in various software systems. The vulnerability is particularly concerning because it affects core system utilities that are frequently used in automated build processes and deployment workflows.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be leveraged to disrupt legitimate software development and deployment processes. When the strip utility crashes due to this invalid read condition, it prevents developers from properly preparing binaries for distribution, potentially causing build failures and deployment interruptions. The vulnerability can be triggered through malformed input files that contain specially crafted headers designed to exploit the missing validation check. This makes it particularly dangerous in environments where automated processing of binary files occurs, as malicious actors could potentially craft input files to cause denial of service attacks against systems running affected versions of Binutils. The crash behavior creates a reliable vector for service disruption, making this vulnerability a significant concern for system administrators and security teams managing software development environments.
Mitigation strategies for CVE-2017-7303 primarily focus on upgrading to patched versions of GNU Binutils where the missing validation check has been implemented in the find_link function. System administrators should prioritize updating their development environments and build servers to versions that contain the fix, which was typically released shortly after the vulnerability disclosure. Additionally, implementing input validation measures at the application level can help reduce the risk of exploitation, particularly in scenarios where untrusted binary files must be processed. Organizations should also consider implementing runtime monitoring and intrusion detection systems to identify potential exploitation attempts, as the crash behavior can be detected through abnormal process termination patterns. The vulnerability demonstrates the importance of proper input validation and memory management in system libraries, aligning with ATT&CK technique T1059.007 which covers the use of system binaries for execution, and reinforces the need for robust software supply chain security practices. Regular security audits of development toolchains and automated patch management systems should be implemented to prevent similar vulnerabilities from being introduced into production environments.