CVE-2025-21618 is a high-severity vulnerability affecting the NiceGUI framework, a Python-based UI tool. This issue allows users to remain authenticated across all browsers, which includes private browsing sessions such as incognito mode. The vulnerability was introduced before version 2.9.1 and has been addressed in the latest update. Given the implications for user privacy and security, this vulnerability is a significant concern.
The severity of this vulnerability is classified as high, with a CVSS score of 7.5. This level of severity indicates that the vulnerability could be exploited with relatively low complexity and does not require any privileges or user interaction, making it particularly concerning. Organizations utilizing NiceGUI should prioritize addressing this vulnerability as it poses a substantial risk to user data.
Currently, the vulnerability status is marked as deferred, meaning further action may still be required. The community should remain vigilant and monitor for updates related to this issue to ensure that all necessary precautions are taken.
Organizations should prioritize patching immediately to mitigate the risk associated with this vulnerability. Failure to address this issue could lead to unauthorized access to sensitive user information.
Vulnerability Details
The official description of CVE-2025-21618 states that it allows users to remain logged in across all browsers, including those in incognito mode. This can lead to potential unauthorized access to user data across different sessions. The vulnerability has been classified under CWE-287, which relates to improper authentication.
The CVSS score of 7.5 indicates high severity, with a vector string of "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N". This implies that the vulnerability can be exploited over the network with low complexity, requires no privileges or user interaction, and impacts the integrity of the application.
The vulnerability was published on January 6, 2025, and is fixed in version 2.9.1 of NiceGUI. Organizations using older versions should upgrade to this latest release to protect against potential exploitation.
Technical Analysis
The root cause of CVE-2025-21618 lies in the authentication mechanism of NiceGUI. Prior to version 2.9.1, the framework did not properly segregate user sessions across different browser contexts, allowing users to remain logged in across incognito sessions. The attack vector is classified as network-based, and the attack complexity is low, meaning that an attacker could exploit this vulnerability without significant effort.
Since the vulnerability requires no privileges and does not need user interaction, it poses a significant risk. The impact on confidentiality is none, while the integrity impact is high, meaning that unauthorized modifications could potentially occur without detection.
Organizations utilizing NiceGUI should assess their exposure to this vulnerability and implement necessary mitigations. The integrity of user sessions must be ensured to prevent unauthorized access to sensitive information.
Risk & Impact Analysis
Risk to organizations includes unauthorized access to user data, which can lead to serious implications for privacy and security. The blast radius of this vulnerability could extend beyond a single user, affecting multiple sessions and environments. Given the high CVSS score, immediate action is warranted.
Organizations should address this vulnerability in their priority patch cycle to mitigate the risk of exposure. The longer this vulnerability remains unaddressed, the higher the risk of potential exploitation.
The urgency of remediation is high, and organizations are encouraged to prioritize updating to NiceGUI version 2.9.1 or later to ensure that they are protected against this vulnerability.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions are all prior to NiceGUI 2.9.1. Organizations utilizing older versions should upgrade to the latest release to ensure their systems are secured against this vulnerability.
Mitigation & Remediation
Immediate remediation requires upgrading to NiceGUI version 2.9.1 or later. Organizations should review their usage of NiceGUI and assess the urgency of patching this vulnerability in their systems.
For organizations unable to immediately upgrade, implementing strict session management practices and monitoring for unusual authentication behaviors can help mitigate risks temporarily. Additionally, conducting regular security assessments and penetration testing can help identify potential vulnerabilities within applications.
For further details on security testing, organizations should consider engaging in penetration testing to validate the effectiveness of their remediation efforts.
Detection Guidance
To effectively monitor for potential exploitation of this vulnerability, organizations should implement logging for authentication events. Indicators such as simultaneous logins from different locations or unusual session behaviors should be flagged for further investigation.
Behavioral anomalies can also signal attempts to exploit this vulnerability. Establishing network signatures to detect unauthorized access attempts can further enhance organizational defenses.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-21618 emphasizes the need for robust authentication mechanisms in modern applications. This vulnerability highlights a critical gap in session management that security teams must address proactively.
Organizations should learn from this incident and implement comprehensive session management protocols to avoid similar vulnerabilities in the future. Regularly reviewing authentication flows and conducting security assessments will strengthen overall application security.
For further insights on enhancing security measures, organizations can explore our penetration testing methodology and best practices.
Additionally, it is advisable to stay informed about emerging vulnerabilities through resources such as our vulnerability management program design guide.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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