CVE-2020-13768 in MiniShare
Summary
by MITRE
In MiniShare before 1.4.2, there is a stack-based buffer overflow via an HTTP PUT request, which allows an attacker to achieve arbitrary code execution, a similar issue to CVE-2018-19861, CVE-2018-19862, and CVE-2019-17601. NOTE: this product is discontinued.
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Analysis
by VulDB Data Team • 06/05/2020
The vulnerability identified as CVE-2020-13768 represents a critical stack-based buffer overflow flaw in MiniShare versions prior to 1.4.2, exposing systems to remote arbitrary code execution capabilities. This vulnerability specifically manifests through HTTP PUT requests, making it particularly dangerous in networked environments where such requests are processed. The flaw shares similarities with other documented vulnerabilities including CVE-2018-19861, CVE-2018-19862, and CVE-2019-17601, indicating a pattern of insecure buffer handling within the affected software ecosystem. The stack-based nature of this buffer overflow means that malicious input can overwrite adjacent memory locations on the program's call stack, potentially allowing attackers to redirect program execution flow and inject malicious code.
The technical implementation of this vulnerability stems from inadequate input validation and bounds checking within the HTTP PUT request processing functionality of MiniShare. When the application receives a PUT request containing oversized data, it fails to properly validate the input length against the allocated buffer size, resulting in memory corruption. This memory corruption can be exploited to overwrite return addresses, function pointers, or other critical stack data structures, enabling attackers to inject and execute arbitrary code on the target system. The vulnerability's exploitation requires an attacker to craft a specific HTTP PUT request with maliciously sized payload data, making it a targeted attack vector rather than a widespread automated threat.
The operational impact of CVE-2020-13768 extends beyond simple code execution, as successful exploitation can lead to complete system compromise and persistent access. Attackers can leverage this vulnerability to install backdoors, escalate privileges, exfiltrate sensitive data, or use the compromised system as a pivot point for further network infiltration. The vulnerability's classification under CWE-121 stack-based buffer overflow highlights the fundamental issue of insufficient bounds checking and improper memory management practices. This weakness aligns with ATT&CK technique T1059.007 for command and scripting interpreter, where attackers can execute arbitrary commands through the compromised system. The discontinued nature of MiniShare does not diminish the importance of understanding this vulnerability, as similar patterns persist in other software implementations and can serve as reference points for identifying comparable flaws in current systems.
Mitigation strategies for CVE-2020-13768 primarily focus on upgrading to MiniShare version 1.4.2 or later, which includes proper input validation and buffer size checking mechanisms. Organizations should implement network segmentation to limit exposure of vulnerable systems, disable unnecessary HTTP PUT methods where possible, and deploy intrusion detection systems to monitor for suspicious PUT request patterns. Additionally, regular security audits should verify that no instances of the vulnerable software remain operational within the network infrastructure. The vulnerability serves as a reminder of the critical importance of input validation and memory safety practices in software development, particularly when handling network-received data. Security teams should also consider implementing application whitelisting and mandatory access controls to limit potential exploitation impact even if such vulnerabilities are present in other software components.