CVE-2006-1061 in cURL
Summary
by MITRE
Heap-based buffer overflow in cURL and libcURL 7.15.0 through 7.15.2 allows remote attackers to execute arbitrary commands via a TFTP URL (tftp://) with a valid hostname and a long path.
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Analysis
by VulDB Data Team • 06/15/2019
The vulnerability identified as CVE-2006-1061 represents a critical heap-based buffer overflow affecting cURL and libcURL versions 7.15.0 through 7.15.2. This flaw specifically manifests when processing TFTP (Trivial File Transfer Protocol) URLs, creating a pathway for remote attackers to execute arbitrary code on vulnerable systems. The vulnerability operates through a carefully crafted TFTP URL that contains a valid hostname alongside an excessively long path parameter, triggering the buffer overflow condition within the library's memory management routines.
The technical implementation of this vulnerability stems from inadequate input validation and bounds checking within the TFTP URL parsing functionality. When cURL processes a TFTP URL, it allocates heap memory to store the path component of the URL, but fails to properly verify the length of this input before copying it into a fixed-size buffer. This classic buffer overflow scenario occurs because the application does not enforce length constraints on the path parameter, allowing attackers to exceed the allocated buffer space and overwrite adjacent memory locations. The heap-based nature of the overflow means that the vulnerability can be exploited to manipulate heap metadata, potentially leading to code execution or denial of service conditions.
The operational impact of this vulnerability extends beyond simple command execution, as it provides attackers with the capability to gain unauthorized control over systems running vulnerable versions of cURL or applications that depend on libcURL. Since TFTP is commonly used for file transfers in network environments, particularly in embedded systems and network infrastructure devices, this vulnerability could be leveraged to compromise a wide range of networked equipment. The remote exploitation aspect eliminates the need for local access, making it particularly dangerous for systems that process untrusted network input. Attackers could potentially use this vulnerability to install malware, establish backdoors, or perform other malicious activities that compromise system integrity and confidentiality.
Organizations using affected versions of cURL or libcURL should immediately implement mitigations to protect against exploitation of this vulnerability. The primary recommended action involves upgrading to cURL version 7.15.3 or later, which includes patches that address the buffer overflow condition through proper input validation and bounds checking. Additionally, network administrators should consider implementing URL filtering mechanisms that can identify and block suspicious TFTP URLs containing excessively long path parameters. This vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and demonstrates characteristics consistent with attack patterns found in the MITRE ATT&CK framework under the 'Execution' and 'Command and Control' phases, where adversaries leverage software vulnerabilities to execute malicious code remotely. The vulnerability serves as a reminder of the critical importance of input validation and proper memory management in preventing remote code execution exploits.