CVE-2022-39280 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting the Python package 'dparse' maintained by pyupio. dparse is a tool used to parse Python dependency files, including index server URLs. Versions of dparse prior to 0.5.2 contain a regular expression that is vulnerable to Regular Expression Denial of Service (ReDoS). This vulnerability arises because the regular expression used to parse index server URLs can be exploited with specially crafted input strings that cause excessive backtracking, leading to high CPU usage and potentially causing the application to become unresponsive or crash. The vulnerability affects all users who parse index server URLs with dparse versions earlier than 0.5.2. The issue was addressed in version 0.5.2 by patching the problematic regular expression. Users who cannot upgrade to 0.5.2 are advised to avoid passing index server URLs in the source files to be parsed to mitigate the risk. There are no known exploits in the wild at this time, but the vulnerability poses a risk of denial of service through resource exhaustion if exploited. The vulnerability was published on October 6, 2022, and has been enriched by CISA, indicating recognition by cybersecurity authorities. The nature of the vulnerability means that an attacker could cause a denial of service condition by supplying malicious input to the parsing function, impacting availability but not directly compromising confidentiality or integrity.

For European organizations, the primary impact of this vulnerability is the potential for denial of service attacks targeting systems that utilize dparse for dependency parsing, particularly in automated build, deployment, or continuous integration pipelines. If an attacker can supply maliciously crafted index server URLs to these systems, they could cause excessive CPU consumption, leading to service degradation or outages. This could disrupt software development workflows, delay deployments, and reduce operational efficiency. Organizations relying on automated dependency management tools that incorporate dparse are at risk. While the vulnerability does not directly expose sensitive data or allow code execution, the availability impact can have downstream effects on business continuity and productivity. Additionally, organizations in sectors with stringent uptime requirements, such as finance, healthcare, and critical infrastructure, may experience heightened operational risks. Given that dparse is a Python package, organizations heavily invested in Python-based development environments are more susceptible. The lack of known exploits reduces immediate risk, but the ease of triggering ReDoS conditions means that opportunistic attackers could exploit this vulnerability if systems are exposed or improperly sanitized.

1. Immediate upgrade to dparse version 0.5.2 or later is the most effective mitigation to eliminate the vulnerability. 2. For environments where upgrading is not immediately feasible, implement input validation and sanitization to prevent untrusted or malformed index server URLs from being parsed. Specifically, restrict or sanitize inputs to exclude potentially malicious regular expression patterns or excessively long strings that could trigger ReDoS. 3. Employ runtime resource monitoring and limits (e.g., CPU timeouts, memory usage caps) on processes invoking dparse to detect and mitigate resource exhaustion conditions early. 4. Integrate static code analysis or dependency scanning tools in CI/CD pipelines to identify usage of vulnerable dparse versions and enforce upgrade policies. 5. Isolate parsing operations in sandboxed or containerized environments to contain potential denial of service impacts. 6. Maintain awareness of dependency updates and subscribe to security advisories related to Python package ecosystems to respond promptly to similar vulnerabilities. 7. Review and harden access controls to ensure that only trusted inputs reach the parsing components, reducing the attack surface.