CVE-2021-28308 in fltk Crate
Summary
by MITRE • 03/12/2021
An issue was discovered in the fltk crate before 0.15.3 for Rust. There is an out-of bounds read because the pixmap constructor lacks pixmap input validation.
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Analysis
by VulDB Data Team • 04/01/2021
The vulnerability identified as CVE-2021-28308 resides within the fltk crate version 0.15.2 and earlier, representing a critical out-of-bounds read flaw that impacts Rust applications utilizing the Fast Light Toolkit for graphical user interface development. This issue manifests specifically within the pixmap constructor functionality, where insufficient input validation allows maliciously crafted pixmap data to trigger memory access violations. The flaw occurs when the application processes pixmap images through the fltk crate's pixmap constructor, which fails to properly validate the input parameters before attempting to read from memory locations beyond the allocated buffer boundaries.
This vulnerability falls under the CWE-129 weakness category, specifically addressing inadequate input validation that leads to out-of-bounds memory access conditions. The technical implementation flaw stems from the pixmap constructor's failure to verify the dimensions and data boundaries of incoming pixmap parameters, creating opportunities for attackers to manipulate memory access patterns through crafted input sequences. When the constructor processes invalid pixmap data, it attempts to read memory locations that may contain sensitive information or trigger application crashes, potentially leading to denial of service conditions or more severe exploitation scenarios.
The operational impact of this vulnerability extends beyond simple application instability, as it creates potential attack vectors for remote code execution or information disclosure when applications process untrusted pixmap data. Systems utilizing the affected fltk crate version are particularly vulnerable when processing pixmap files from external sources, web applications, or user-generated content that may contain maliciously formatted image data. The vulnerability's exploitation potential increases when applications lack proper input sanitization mechanisms, making it particularly dangerous in environments where pixmap data originates from untrusted sources.
Security mitigations for CVE-2021-28308 primarily involve upgrading to fltk crate version 0.15.3 or later, which includes comprehensive input validation within the pixmap constructor to prevent out-of-bounds memory access. Organizations should also implement defensive programming practices such as input sanitization, memory boundary checks, and proper error handling when processing pixmap data. Additionally, application developers should consider implementing runtime checks and validation layers that can detect and reject malformed pixmap data before it reaches the vulnerable constructor functions. The mitigation strategy aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as attackers may attempt to exploit this vulnerability through crafted input to gain unauthorized access or execute arbitrary code within the application context.