CVE-2000-0973 in cURL
Summary
by MITRE
Buffer overflow in curl earlier than 6.0-1.1, and curl-ssl earlier than 6.0-1.2, allows remote attackers to execute arbitrary commands by forcing a long error message to be generated.
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Analysis
by VulDB Data Team • 09/13/2024
The vulnerability identified as CVE-2000-0973 represents a critical buffer overflow flaw affecting early versions of the curl command-line tool and curl-ssl utility. This security weakness exists in curl versions prior to 6.0-1.1 for standard curl and 6.0-1.2 for curl-ssl implementations. The vulnerability stems from inadequate input validation and memory management within the error handling mechanisms of these networking utilities. Attackers can exploit this flaw by crafting specially designed network requests that generate exceptionally long error messages, which then trigger the buffer overflow condition when processed by the vulnerable curl applications. The flaw specifically manifests when the application attempts to store error information in a fixed-size buffer that cannot accommodate the excessive length of the generated error message, leading to memory corruption that can be leveraged for malicious purposes.
The technical exploitation of this buffer overflow vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. This particular implementation vulnerability demonstrates how network-based applications can become susceptible to remote code execution when error handling routines fail to properly validate input lengths. The attack vector operates through network communication channels where curl is used to fetch resources from remote servers, making it particularly dangerous in automated systems or when curl is invoked with untrusted network inputs. The vulnerability's classification as a remote code execution flaw indicates that attackers do not require local system access or authentication to exploit this weakness, making it especially concerning for systems that rely on curl for automated network operations and web scraping activities.
The operational impact of CVE-2000-0973 extends beyond simple denial of service scenarios, as the buffer overflow condition creates opportunities for arbitrary code execution on affected systems. When successfully exploited, this vulnerability allows remote attackers to execute malicious code with the privileges of the user running the vulnerable curl application, potentially leading to complete system compromise. Systems that regularly use curl for automated tasks, web service integration, or network monitoring become particularly vulnerable, as attackers can craft malicious network responses that trigger the overflow condition. The vulnerability's presence in both standard curl and curl-ssl implementations means that organizations using either version are at risk, regardless of whether SSL/TLS encryption is employed. This affects a broad range of network operations including automated backup systems, web crawling applications, and integration tools that depend on curl for HTTP/HTTPS communication protocols.
Organizations should implement immediate mitigation strategies including updating to curl versions 6.0-1.1 or later for standard curl installations and 6.0-1.2 or later for curl-ssl implementations. The vulnerability's classification under the ATT&CK framework as a remote code execution technique through buffer overflow vulnerabilities indicates that defensive measures should include network segmentation, application whitelisting, and monitoring for unusual curl usage patterns. System administrators should also consider implementing intrusion detection systems that can identify potential exploitation attempts through anomalous network traffic patterns or unexpected curl process execution. Additionally, organizations should review their automated processes that rely on curl to ensure proper input validation and error handling practices are implemented to prevent exploitation of similar vulnerabilities in other components of their network infrastructure. The remediation process should include comprehensive testing of updated curl versions to ensure compatibility with existing network automation scripts and integration workflows while maintaining security posture against this and related buffer overflow threats.