CVE-2015-0843 in yubiserver
Summary
by MITRE • 06/27/2025
yubiserver before 0.6 is to buffer overflows due to misuse of sprintf.
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Analysis
by VulDB Data Team • 06/30/2025
The vulnerability identified as CVE-2015-0843 affects yubiserver versions prior to 0.6, presenting a critical buffer overflow condition that stems from improper usage of the sprintf function within the software's codebase. This flaw represents a classic example of insecure coding practices that can lead to arbitrary code execution and system compromise. The vulnerability specifically manifests when the application processes user input through sprintf without adequate bounds checking or input validation, creating opportunities for attackers to manipulate memory layout and potentially execute malicious code.
The technical implementation of this vulnerability involves the misuse of the sprintf function, which lacks built-in bounds checking mechanisms that would normally prevent buffer overflows. When yubiserver processes authentication requests or other user-provided data, it employs sprintf to format strings for storage or transmission without verifying that the resulting output will fit within allocated memory buffers. This pattern directly aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflow scenarios. The vulnerability demonstrates poor input handling practices that violate fundamental security principles for memory management and data validation.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable full system compromise. An attacker who successfully exploits this buffer overflow could overwrite adjacent memory locations, potentially corrupting program execution flow or injecting malicious code into the application's memory space. This type of vulnerability falls under the ATT&CK framework's technique T1059, which covers command and scripting interpreter usage, as exploitation may involve executing arbitrary commands through controlled memory corruption. The affected yubiserver application, which serves as a critical component in authentication infrastructure, could provide attackers with unauthorized access to protected systems and services.
Mitigation strategies for CVE-2015-0843 require immediate patching of affected yubiserver installations to version 0.6 or later, where the buffer overflow conditions have been addressed through proper input validation and secure string handling practices. Organizations should implement comprehensive code review processes that specifically target sprintf and related functions, ensuring that all string formatting operations include appropriate buffer size checks and bounds validation. The remediation approach should also incorporate defensive programming techniques such as using safer alternatives like snprintf, which provide explicit buffer size parameters to prevent overflow conditions. Additionally, network segmentation and access controls should be implemented to limit exposure of vulnerable yubiserver instances, while continuous monitoring and intrusion detection systems should be configured to identify potential exploitation attempts targeting this specific vulnerability class.