This vulnerability allows for relative path traversal in the TZInfo Ruby library, impacting versions prior to 0.36.1 and 1.2.10 when used with the Ruby data source tzinfo-data. The vulnerability arises from the failure of `TZInfo::Timezone.get` to validate time zone identifiers properly, which can lead to unintended file loading through the `require` command in Ruby. This issue requires immediate attention as it can result in unauthorized access to sensitive files within the Ruby process.
The severity rating for this vulnerability is high, with a CVSS score of 7.5. The potential risk to organizations includes unauthorized access to confidential data, integrity issues, and availability impacts due to the exploitation of this flaw. Attackers may leverage this vulnerability to load arbitrary files by manipulating the time zone identifier.
Organizations should prioritize patching immediately. Versions 0.3.61 and 1.2.10 include fixes that properly validate time zone identifiers and mitigate this issue. Notably, versions 2.0.0 and later are not vulnerable. If updating is not immediately possible, applications can implement a validation mechanism for time zone identifiers to conform to specific regular expression patterns before invoking `TZInfo::Timezone.get`.
Given the potential for exploitation, it is critical for organizations using affected versions of the TZInfo Ruby library to assess their current implementations and apply necessary updates to safeguard against this vulnerability.
Vulnerability Details
The vulnerability in TZInfo, which provides access to time zone data and facilitates time conversions, relates to improper validation of time zone identifiers in versions prior to 0.36.1 and 1.2.10 when utilized with the tzinfo-data Ruby data source. The vulnerability was published on July 22, 2022, and has been classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-23 (Relative Path Traversal).
The CVSS score of 7.5 indicates high severity due to the high potential for exploitation. The attack vector is network-based, with high attack complexity and no privileges required for exploitation. User interaction is required, adding another layer of complexity to the attack surface.
Affected products include TZInfo and Debian Linux. Organizations using these components should ensure they are on patched versions to avoid exploitation.
Technical Analysis
The root cause of this vulnerability is the improper validation of time zone identifiers in the TZInfo library. Specifically, `TZInfo::Timezone.get` fails to sanitize input correctly, allowing attackers to inject new line characters into the identifier, facilitating the loading of arbitrary files. This flaw is particularly concerning for Ruby versions 1.9.3 and later, where unintended files can be executed within the Ruby process.
The attack vector is network-based, as it requires an attacker to supply a crafted request that exploits the vulnerability. The attack complexity is assessed as high, as it necessitates user interaction to exploit the flaw fully. No privileges are required for the attacker to execute the exploit, which amplifies the risk.
The impacts on confidentiality, integrity, and availability are all rated high, indicating that successful exploitation could lead to significant breaches in security. Organizations must remain vigilant and proactive in their approach to securing applications that utilize the TZInfo library.
Risk & Impact Analysis
The real-world deployment risk associated with this vulnerability is substantial. Organizations using vulnerable versions of TZInfo may face unauthorized access to sensitive data, potentially leading to confidentiality breaches. The blast radius is extensive, as this library is often integrated into various applications, increasing the likelihood of exploitation across different systems.
The urgency assessment, based on the CVSS score and the potential for exploitation, is high. Organizations should prioritize addressing this vulnerability in their patch management cycles to mitigate risks effectively. The risk of exploitation amplifies as organizations expose their applications to the internet, making it crucial to remediate this vulnerability swiftly.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of TZInfo include all versions prior to 0.36.1 and those prior to 1.2.10 when used with the Ruby data source tzinfo-data. Specifically, organizations should focus on versions 0.3.61 and 1.2.10, which include necessary fixes for this vulnerability.
Mitigation & Remediation
Organizations should prioritize patching immediately. To mitigate this vulnerability, upgrade to TZInfo version 0.3.61 or 1.2.10 or later. If upgrading is not feasible, a temporary workaround involves validating the time zone identifiers using the regular expression `\A[A-Za-z0-9+\-_]+(?:\/[A-Za-z0-9+\-_]+)*\z` to ensure they do not contain malicious characters.
Additionally, organizations should ensure that untrusted files are not placed in directories on the Ruby load path to prevent unauthorized file loading through the TZInfo library.
For further assistance, organizations may consider engaging with experts in application security, such as penetration testing services to validate the effectiveness of their remediation efforts.
Detection Guidance
Organizations should monitor logs for indicators of unauthorized access attempts, specifically looking for anomalies in time zone data processing. Additionally, monitoring for unusual behaviors in applications utilizing TZInfo can help identify potential exploitation attempts.
Network signatures may also be beneficial in detecting attempts to exploit this vulnerability, especially those that attempt to load arbitrary files through crafted time zone identifiers.
AppSecure Threat Intelligence Insight
This vulnerability highlights the importance of input validation in software development. Security teams should ensure comprehensive validation mechanisms are in place to prevent similar vulnerabilities from emerging. Regular security assessments and code reviews can significantly mitigate risks associated with such vulnerabilities.
Security teams should also familiarize themselves with common patterns of vulnerabilities related to improper input validation, such as those seen in this case with TZInfo. Educating developers and conducting training sessions on secure coding practices is crucial to maintaining a secure codebase.
For more insights, organizations may refer to our detailed guides on penetration testing methodology and vulnerability management programs to enhance their security posture.
The lessons learned from this vulnerability should serve as a guide for future development practices, ensuring that security is integrated into the software development lifecycle.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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