A high-severity vulnerability has been identified in pyjwt v2.10.1, which allows weak encryption. This vulnerability is classified as CVSS 7.0, indicating significant risk to organizations that utilize this library for JSON Web Token (JWT) implementations. The weakness arises from the choice of key lengths, which are determined by the applications using the library. While the supplier disputes the claims regarding weak encryption, they acknowledged that users may benefit from a minimum key length and stricter enforcement mechanisms.
Risk to organizations includes potential exposure to unauthorized access if weak encryption practices are exploited. The fact that this vulnerability remains unaddressed in the specific version increases the urgency for organizations to evaluate their use of the affected library. Given the nature of the vulnerability, it is crucial for defenders to prioritize patching immediately.
Currently, there are no known exploits for this vulnerability, reducing the immediate risk of active attacks. However, the lack of public exploit information does not diminish the need for swift remediation. Organizations should assess their implementations and ensure compliance with best practices regarding encryption standards.
Patching should be implemented as soon as possible to mitigate any risks associated with this vulnerability. Organizations utilizing pyjwt should be vigilant and prepare for potential future disclosures regarding exploit techniques.
Vulnerability Details
The vulnerability identified as CVE-2025-45768 relates to weak encryption found in pyjwt version 2.10.1. The CVSS score of 7 classifies this vulnerability as high severity. Officially, this vulnerability allows applications to select key lengths that could lead to weak encryption practices, which may not meet security standards. The supplier's stance on the disputed nature of the vulnerability is noteworthy, suggesting that while user choice exists, there is a lack of enforcement mechanisms that could enhance security.
The CVSS vector indicates the attack vector is network-based (AV:N), with high complexity (AC:H) and no privileges required (PR:N). There is no user interaction needed (UI:N), and the impact on confidentiality is low (C:L), while integrity impact is also low (I:L), but availability impact is high (A:H). The affected product is pyjwt, which is developed by pyjwt_project.
This vulnerability was published on July 31, 2025, and is recorded under CWE-311, which corresponds to 'Missing Authentication for Critical Function'.
Technical Analysis
The root cause of CVE-2025-45768 is linked to the design choice of allowing applications to define encryption key lengths. This flexibility can lead to weak encryption if users do not adhere to secure key length standards. The attack vector is classified as network-based, suggesting that exploitation could occur remotely without physical access to the system.
The attack complexity is assessed as high, meaning that an attacker may need significant expertise or specific conditions to exploit the vulnerability effectively. Importantly, no privileges are required to exploit this vulnerability, making it more accessible to potential attackers. Additionally, user interaction is not required, which further increases the risk.
Considering the impacts, the confidentiality and integrity impacts are evaluated as low, which indicates minimal risk to sensitive data exposure and corruption. However, the high availability impact suggests that successful exploitation could disrupt services relying on the library.
Risk & Impact Analysis
Real-world deployment of pyjwt v2.10.1 carries significant risks, especially for organizations that handle sensitive information or rely heavily on secure token implementations. The potential for unauthorized access through weak encryption practices poses a direct threat to data integrity and availability.
Organizations should assess the blast radius of this vulnerability. If exploited, it could allow attackers to manipulate token-based authentication processes, leading to unauthorized operations and data breaches. This vulnerability also represents a critical reminder of the importance of adhering to encryption best practices, especially in libraries handling sensitive data.
Given the CVSS score and the lack of KEV status, the urgency assessment indicates that organizations should address this vulnerability in their priority patch cycle. The risk remains significant, especially if the library is integrated into critical systems.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected version is pyjwt 2.10.1. Organizations using this version should consider upgrading to a more secure version or implementing necessary configurations to enforce stronger encryption practices. If version information is missing, it is important to note that all versions prior to the vendor patch may be affected.
Mitigation & Remediation
Organizations are advised to patch or upgrade their pyjwt library to the latest version as soon as possible to mitigate the risks associated with CVE-2025-45768. If the patch is unavailable, it is crucial to implement configuration hardening to enforce stronger encryption standards. This may include setting minimum key lengths and ensuring that applications utilizing the library follow secure coding practices.
Additionally, organizations should consider implementing network controls to limit exposure and monitor usage of the library to detect any potential vulnerabilities. Monitoring logs for anomalies and ensuring that proper security measures are in place can help in identifying any exploitation attempts.
Organizations should validate remediation through penetration testing to identify similar weaknesses.
Detection Guidance
To detect potential exploitation of CVE-2025-45768, organizations should monitor logs for unusual authentication patterns and token generation activities. Additionally, behavioral anomalies that deviate from standard operations may indicate attempts to exploit weak encryption practices.
Network signatures that identify unauthorized access attempts or token manipulation should also be established. Regular audits of systems utilizing the pyjwt library can aid in identifying any misconfigurations or weaknesses in encryption practices.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-45768 underscores the persistent issues associated with encryption practices in software libraries. This vulnerability exemplifies the need for developers to prioritize security by design, especially in widely used libraries handling sensitive data. It is imperative for organizations to adopt robust security measures and ensure compliance with established best practices.
The pattern represented by this vulnerability reflects a trend in software development where flexibility in security features can lead to potential risks. Security teams must remain vigilant and proactively assess their software components for vulnerabilities. The lessons learned from this incident highlight the importance of enforcing strong defaults and educating developers on the implications of their security design choices.
Strategically, organizations should invest in comprehensive security testing, such as continuous security testing, to identify and remediate vulnerabilities as they arise.
Furthermore, organizations can enhance their security posture by adopting a comprehensive application security assessment strategy, ensuring that all components of their software ecosystem are scrutinized for vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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