CVE-2022-42964 is a vulnerability identified in the pymatgen Python package, specifically related to the GaussianInput.from_string method. The issue stems from inefficient regular expression handling, classified under CWE-1333, which leads to an exponential Regular Expression Denial of Service (ReDoS). This vulnerability allows an attacker to supply crafted input strings that cause the regular expression engine to consume excessive CPU resources, effectively leading to a denial of service by slowing down or halting the processing of legitimate requests. The vulnerability affects all versions of pymatgen prior to a fix, as indicated by the affectedVersions field listing version "0" (likely meaning all versions before a patch). The CVSS 3.1 base score is 5.9, categorized as medium severity, with vector AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H. This means the attack can be executed remotely over the network without authentication or user interaction, but requires high attack complexity. The impact is limited to availability, with no confidentiality or integrity loss. No known exploits in the wild have been reported, and no official patches are linked in the provided data. Pymatgen is a widely used Python library in materials science for analyzing and manipulating molecular and crystal structures, often used in academic and industrial research environments. The vulnerability could be exploited by attackers who can supply arbitrary input to the vulnerable method, potentially causing denial of service in systems processing such inputs, which may include automated pipelines or web services integrating pymatgen functionality.

For European organizations, especially those involved in scientific research, materials science, and computational chemistry, this vulnerability could disrupt critical workflows that rely on pymatgen for data processing and simulation input generation. Denial of service conditions could lead to downtime in research computing environments, delaying experiments and analysis. Industrial entities using pymatgen in product development or quality control could experience operational interruptions. Since the vulnerability does not impact confidentiality or integrity, data breaches or manipulation are unlikely. However, availability impacts could affect productivity and service reliability. The medium CVSS score and high attack complexity reduce the likelihood of widespread exploitation, but organizations with exposed services or automated systems accepting untrusted input should be cautious. The lack of known exploits in the wild suggests limited active targeting, but the potential for denial of service in critical scientific infrastructure warrants attention.

Organizations should audit their use of pymatgen, particularly any components or services that utilize the GaussianInput.from_string method with input from untrusted or external sources. Where possible, restrict or sanitize inputs to this method to prevent maliciously crafted strings that could trigger the ReDoS condition. Implement input validation and length checks before processing. Consider isolating pymatgen processing tasks in resource-limited environments or containers to mitigate the impact of potential CPU exhaustion. Monitor system performance for unusual spikes in CPU usage during pymatgen operations. Since no official patches are linked, track pymatgen project repositories and PyPI for updates or security advisories addressing this issue and apply patches promptly once available. Additionally, consider implementing rate limiting or request throttling on services exposing pymatgen functionality to reduce the risk of denial of service. For critical environments, explore alternative libraries or custom parsing implementations that do not rely on vulnerable regular expressions until a fix is released.