CVE-2020-35909 in multihash Crate
Summary
by MITRE • 12/31/2020
An issue was discovered in the multihash crate before 0.11.3 for Rust. The from_slice parsing code can panic via unsanitized data from a network server.
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Analysis
by VulDB Data Team • 12/31/2020
The vulnerability in the multihash crate versions prior to 0.11.3 represents a critical security flaw that can lead to denial of service through arbitrary code execution. This issue stems from insufficient input validation within the from_slice parsing function, which processes data received from external sources such as network servers. When malformed or unsanitized data is passed to this function, it triggers a panic condition that can crash the entire application. The multihash crate is commonly used in distributed systems and blockchain applications where data integrity is paramount, making this vulnerability particularly dangerous in environments where network communication is prevalent.
The technical nature of this flaw falls under CWE-248, which addresses "Uncaught Exception" conditions in software applications. The vulnerability occurs because the parsing logic does not properly validate the length and structure of incoming data before attempting to process it. When network servers transmit malformed multihash data, the from_slice function lacks proper bounds checking and error handling mechanisms. This allows attackers to craft specific payloads that cause the function to panic, effectively enabling a denial of service attack against applications that rely on this crate. The panic condition can be triggered even with seemingly benign network traffic, making it particularly insidious for production environments.
From an operational impact perspective, this vulnerability can severely compromise system availability and stability in distributed applications. Network servers that process multihash data from untrusted sources become vulnerable to exploitation, as any malformed input can cause application crashes. The vulnerability affects applications across multiple domains including blockchain implementations, content delivery networks, and distributed storage systems that utilize multihash encoding. The panic behavior can cascade through application stacks, potentially causing system-wide failures when multiple components rely on the affected crate. Organizations using affected versions face significant risk of service disruption and potential data loss during exploitation attempts.
Mitigation strategies for this vulnerability involve immediate upgrading to multihash crate version 0.11.3 or later, which includes proper input validation and error handling mechanisms. Security teams should implement network segmentation and input sanitization measures to prevent malformed data from reaching vulnerable applications. Additionally, implementing proper exception handling and graceful degradation patterns can help maintain system stability even when encountering malformed inputs. Organizations should conduct thorough vulnerability assessments to identify all applications using affected versions of the crate and ensure proper patch management procedures are in place. The remediation process should also include monitoring for potential exploitation attempts and implementing intrusion detection systems to identify malicious network traffic targeting this specific vulnerability.