CVE-2023-42444 in rust-phonenumber
Summary
by MITRE • 09/19/2023
phonenumber is a library for parsing, formatting and validating international phone numbers. Prior to versions `0.3.3+8.13.9` and `0.2.5+8.11.3`, the phonenumber parsing code may panic due to a panic-guarded out-of-bounds access on the phonenumber string. In a typical deployment of `rust-phonenumber`, this may get triggered by feeding a maliciously crafted phonenumber over the network, specifically the string `.;phone-context=`. Versions `0.3.3+8.13.9` and `0.2.5+8.11.3` contain a patch for this issue. There are no known workarounds.
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Analysis
by VulDB Data Team • 10/13/2023
The vulnerability identified as CVE-2023-42444 affects the rust-phonenumber library, a widely-used Rust implementation for parsing, formatting, and validating international phone numbers. This library serves as a critical component in numerous applications that process user-provided phone number data, making it a potential attack surface for adversaries seeking to exploit application stability and availability. The vulnerability manifests as a panic condition that occurs during the parsing phase of phone number strings, specifically when encountering malformed input that triggers an out-of-bounds memory access pattern within the library's internal processing logic.
The technical flaw resides in the library's string parsing mechanism where an unguarded bounds check leads to a memory access violation when processing specific malicious input patterns. The particular string `.;phone-context=` serves as the trigger for this vulnerability, exploiting a race condition or improper input validation that causes the application to crash rather than gracefully handling the malformed data. This type of vulnerability falls under CWE-129, which describes improper validation of array indices, and represents a classic example of an out-of-bounds read error that can be leveraged for denial-of-service attacks. The panic-guarded nature of the vulnerability indicates that the library's defensive mechanisms are insufficient to prevent the memory access violation from occurring.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be exploited in network-facing applications where phone number data is processed from untrusted sources. Attackers can craft malicious phone number strings that, when processed by vulnerable versions of the library, cause the application to terminate unexpectedly, leading to service disruption and potential information disclosure through crash dumps. This vulnerability is particularly concerning in systems where phone number validation is part of authentication flows or user registration processes, as it can be used to disrupt legitimate service operations and potentially reveal system information through crash artifacts. The vulnerability's presence in widely-deployed libraries means that numerous applications across different domains could be affected, from web applications to mobile services and backend systems processing user data.
Mitigation strategies for CVE-2023-42444 require immediate upgrade to patched versions 0.3.3+8.13.9 or 0.2.5+8.11.3, as no effective workarounds exist for this particular vulnerability. Organizations should conduct comprehensive inventory assessments to identify all systems utilizing vulnerable versions of the rust-phonenumber library, particularly focusing on applications that process user-provided phone number data over network interfaces. The patch implementation should be part of a broader security update strategy that includes monitoring for similar vulnerabilities in other third-party dependencies. Additionally, implementing proper input validation and sanitization at application layers can provide defense-in-depth measures, though these cannot replace the necessary library updates. Security teams should also consider implementing intrusion detection systems that monitor for patterns consistent with this vulnerability to detect potential exploitation attempts in production environments. This vulnerability exemplifies the importance of maintaining up-to-date dependencies and the critical nature of rapid response to security advisories affecting widely-used libraries.