CVE-2023-25577 is a high-severity vulnerability affecting Werkzeug, a comprehensive WSGI web application library. This vulnerability allows an attacker to exploit the multipart form data parser, which will parse an unlimited number of parts, including file parts. Prior to version 2.2.3, each part requires CPU time to parse and may use more memory as Python data. If an attacker can send crafted multipart data to an endpoint that processes `request.data`, `request.form`, `request.files`, or `request.get_data(parse_form_data=False)`, it can lead to unexpectedly high resource usage.
The denial of service scenario arises because the CPU time required for parsing can block worker processes from handling legitimate requests. Additionally, the amount of RAM needed can lead to an out of memory kill of the process. If many concurrent requests are sent continuously, this can exhaust or kill all available workers, severely impacting application availability. Organizations should prioritize patching immediately.
This vulnerability has a CVSS score of 7.5, indicating a high severity level, which highlights the importance of addressing it promptly. The vulnerability was published on February 14, 2023, and a patch was included in version 2.2.3 of Werkzeug.
Organizations using affected versions of Werkzeug should assess their risk and implement the necessary updates to mitigate potential exploitation.
Vulnerability Details
The vulnerability affects all versions of Werkzeug prior to 2.2.3 and is classified under CWE-770. The root cause is the lack of limits on multipart form data parsing, which can lead to resource exhaustion. The vulnerability is characterized as having a low attack complexity and requiring no privileges or user interaction, making it straightforward for attackers to exploit.
Technical Analysis
The attack vector is network-based, allowing remote attackers to send specially crafted requests to the server. The attack complexity is low, as no special conditions or complex actions are needed to exploit the vulnerability. Additionally, there are no privileges required to exploit the vulnerability, and it does not require user interaction. The impact on availability is high, as successful exploitation can lead to denial of service by exhausting server resources.
Risk & Impact Analysis
Risk to organizations includes significant application downtime and potential loss of service availability due to resource exhaustion. The vulnerability's high exploitability means that it can be easily targeted in active attacks, making it critical for affected organizations to address it. The CVSS score of 7.5 indicates a high risk level, suggesting that organizations should address this vulnerability in priority patch cycles.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions of Werkzeug prior to version 2.2.3 are affected by this vulnerability. Organizations should upgrade to version 2.2.3 or later to mitigate this risk.
Mitigation & Remediation
To address this vulnerability, organizations should apply the patch available in Werkzeug version 2.2.3. If immediate patching is not feasible, consider implementing workarounds such as limiting the size of multipart requests or monitoring for unusual traffic patterns that could indicate exploitation attempts. Configuration hardening and network controls can also help mitigate potential risks.
Detection Guidance
Security teams should monitor logs for indicators of abuse related to multipart form submissions. Look for anomalous patterns such as unusually high numbers of multipart requests or spikes in CPU and memory usage that could indicate an ongoing attack. Network signatures that identify excessive multipart traffic can also aid in detection.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2023-25577 lies in its demonstration of resource exhaustion vulnerabilities in web applications. Security teams should take this as a reminder to implement strict limits on resource usage in their applications, especially in components like multipart form data parsers. This incident highlights the need for continuous security testing to identify such vulnerabilities early in the development lifecycle.
Organizations are encouraged to enhance their vulnerability management programs to include regular assessments and to stay informed about emerging threats. For more information on effective security practices, organizations can refer to the vulnerability management program and the importance of patch management.
Regular security assessments, including penetration testing, can help organizations identify and remediate vulnerabilities before they can be exploited.
In conclusion, CVE-2023-25577 serves as a critical reminder for organizations to maintain vigilance in their security practices and to prioritize the remediation of known vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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