CVE-2026-120451 in libgphoto2
Summary
by MITRE • 11/02/2026
libgphoto2 through 2.5.34 contains stack-based and heap-based buffer overflow vulnerabilities in jl2005c_init() that allow malicious USB devices to corrupt memory by supplying an unbounded allocation table entry count. Attackers can connect a spoofed Jeilin JL2005B/C/D camera reporting 1022 or more entries to overwrite the saved return address and heap data, potentially achieving code execution.
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Analysis
by VulDB Data Team • 11/02/2026
The vulnerability identified in libgphoto2 versions through 2.5.34 represents a critical security flaw rooted in improper input validation within the driver for Jeilin JL2005B/C/D cameras. Specifically, the jl2005c_init() function fails to enforce strict bounds checking on allocation table entry counts received from connected USB devices. This lack of sanitization allows an attacker controlling a malicious or spoofed peripheral device to supply unbounded data that exceeds the expected limits for memory allocation structures. The core technical flaw is classified as CWE-120, Buffer Copy without Checking Size of Input Classic Buffer Overflow, and more specifically involves both stack-based (CWE-121) and heap-based (CWE-122) buffer overflows depending on how the oversized data interacts with local variables versus dynamically allocated memory regions.
When a malicious USB device connects to an affected system, it can report an entry count of 1022 or more during the initialization handshake process. The libgphoto2 library processes this value without adequate verification against predefined maximums for the JL2005 series hardware specifications. Consequently, the application attempts to allocate memory based on this inflated number or writes data into fixed-size buffers using indices derived from the unbounded count. In stack-based scenarios, writing beyond the buffer boundary overwrites adjacent memory locations, including the saved return address and frame pointer. This corruption allows an attacker to redirect program execution flow by replacing the legitimate return address with a payload address pointing to shellcode or other malicious instructions embedded in the overflowed data.
In heap-based exploitation vectors, the oversized allocation triggers writes into dynamically allocated blocks that may be adjacent to critical metadata structures such as chunk headers or function pointers within the heap arena. Overwriting these structures can lead to arbitrary code execution through techniques like controlled free operations or indirect branch hijacking. The operational impact of this vulnerability is severe, as it enables remote code execution on systems where libgphoto2 is used to interact with digital cameras via USB connections. Since many Linux distributions and photography software suites rely heavily on libgphoto2 for device communication, users who connect untrusted or potentially compromised camera hardware are at significant risk. The attack vector aligns with ATT&CK technique T1059, Command and Scripting Interpreter, as the ultimate goal is to execute arbitrary commands within the context of the vulnerable application process.
Mitigation strategies must focus on immediate patching and defensive programming practices. Users should upgrade libgphoto2 to version 2.5.34 or later where these bounds checks have been implemented in the jl2005c_init() function. For environments unable to update immediately, deploying input validation layers at the USB device interface level can help filter out anomalous descriptor data before it reaches the application logic. Additionally, enabling memory protection mechanisms such as Address Space Layout Randomization (ASLR) and Stack Canaries can mitigate exploitation success rates by making precise address prediction difficult for attackers. Security teams should also monitor for unusual process behavior originating from gphoto2 processes to detect potential exploitation attempts in real-time.