CVE-2024-1892 in Scrapy
Summary
by MITRE • 02/28/2024
Parts of the Scrapy API were found to be vulnerable to a ReDoS attack. Handling a malicious response could cause extreme CPU and memory usage during the parsing of its content, due to the use of vulnerable regular expressions for that parsing.
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Analysis
by VulDB Data Team • 05/06/2025
The vulnerability identified as CVE-2024-1892 affects the Scrapy web crawling framework and represents a significant security risk through its susceptibility to Regular Expression Denial of Service attacks. This flaw exists within the API components of Scrapy where regular expressions are employed for parsing response content, creating a pathway for malicious actors to exploit resource consumption patterns that can lead to system degradation or complete service disruption. The vulnerability stems from the improper implementation of regular expression patterns that are vulnerable to catastrophic backtracking when processing malformed input data.
The technical execution of this vulnerability occurs when Scrapy processes HTTP responses containing specifically crafted malicious content that triggers inefficient regular expression matching. The affected parsing logic utilizes regular expressions that are susceptible to exponential time complexity under certain input conditions, causing the parsing engine to consume excessive CPU cycles and memory resources. This behavior manifests as a denial of service condition where legitimate requests cannot be processed due to the system's resources being consumed by the malicious parsing operations. The vulnerability specifically impacts the content parsing mechanisms within Scrapy's API handlers, making it particularly dangerous for applications that rely heavily on automated content processing and web scraping operations.
The operational impact of CVE-2024-1892 extends beyond simple performance degradation to potentially compromise entire web scraping infrastructures and applications. Attackers can leverage this vulnerability to consume disproportionate system resources, leading to service unavailability, increased operational costs, and potential data loss. Organizations running Scrapy-based applications become vulnerable to resource exhaustion attacks that can be executed with minimal effort, making this a particularly concerning security weakness for automated systems that process large volumes of web content. The vulnerability also presents challenges for incident response and forensic analysis due to the subtle nature of the attack vector and the difficulty in distinguishing between legitimate resource consumption and malicious exploitation.
Mitigation strategies for CVE-2024-1892 should focus on immediate remediation through software updates and patching of affected Scrapy versions, while also implementing defensive measures such as input validation and rate limiting to prevent exploitation attempts. Organizations should conduct comprehensive vulnerability assessments of their web scraping infrastructure to identify potential exposure points and implement monitoring solutions that can detect anomalous resource consumption patterns. The fix typically involves replacing vulnerable regular expressions with more efficient alternatives that prevent catastrophic backtracking scenarios, aligning with security best practices outlined in the CWE-400 category for Regular Expression Denial of Service vulnerabilities. Additionally, implementing proper API request throttling and resource allocation controls can provide additional layers of defense against potential exploitation attempts.