CVE-2020-22336 in pdfcrack
Summary
by MITRE • 07/06/2023
An issue was discovered in pdfcrack 0.17 thru 0.18, allows attackers to execute arbitrary code via a stack overflow in the MD5 function.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/24/2023
The vulnerability identified as CVE-2020-22336 represents a critical stack overflow flaw within pdfcrack version 0.17 through 0.18 that exposes systems to arbitrary code execution attacks. This issue specifically targets the MD5 function implementation within the software, creating a dangerous condition where malicious input can overwrite stack memory beyond intended boundaries. The vulnerability arises from insufficient input validation and buffer management during cryptographic hash processing, allowing attackers to craft specially formatted inputs that trigger the overflow condition. Such stack corruption can lead to unpredictable program behavior, including potential remote code execution or system compromise.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking permits memory corruption. The flaw demonstrates characteristics consistent with CWE-787, representing an out-of-bounds write that occurs when the program attempts to write data beyond the allocated stack buffer space. Attackers can exploit this weakness by providing crafted input to the MD5 processing function, causing the stack to overflow and potentially overwrite return addresses or other critical program variables. The vulnerability's impact is particularly severe given that pdfcrack is a tool designed for password recovery and cryptographic analysis, making it a target for adversaries seeking to compromise systems through malicious input manipulation.
From an operational perspective, this vulnerability creates significant risk for organizations that may be using affected versions of pdfcrack in their security testing or forensic analysis workflows. The stack overflow condition can result in application crashes, data corruption, or more dangerously, allow attackers to execute arbitrary code with the privileges of the running process. This threat model aligns with ATT&CK technique T1059.007, which covers script-based execution through command-line interfaces, as the overflow could potentially be leveraged to inject and execute malicious code within the application's execution context. The vulnerability's exploitation requires minimal privileges and can be automated, making it particularly attractive to threat actors seeking to establish persistent access or conduct reconnaissance activities.
Mitigation strategies for CVE-2020-22336 should prioritize immediate remediation through version updates to pdfcrack 0.19 or later, which contain fixed implementations of the MD5 function with proper bounds checking. Organizations should implement input validation measures to restrict the size and format of data processed by the application, particularly when handling cryptographic operations. Network segmentation and access controls should be enforced to limit exposure of systems running vulnerable versions. Additionally, security monitoring should be enhanced to detect anomalous behavior patterns that might indicate exploitation attempts, including unusual memory access patterns or unexpected process termination. Regular vulnerability assessments and penetration testing should be conducted to identify similar issues in other cryptographic libraries or security tools within the organization's infrastructure. The fix implemented in newer versions addresses the root cause by incorporating proper buffer management and input validation techniques that prevent the stack overflow condition from occurring during MD5 hash computations.