CVE-2024-47874 is a high-severity denial of service (DoS) vulnerability impacting the Starlette framework. This vulnerability allows attackers to upload arbitrary large form fields without a filename in multipart/form-data requests, causing excessive memory allocation.
With a CVSS score of 8.7, this vulnerability is serious and requires immediate attention. The absence of effective request size limits can lead to significant slowdowns and potential crashes of applications built on Starlette or FastAPI.
Risk to organizations includes service unavailability, operational disruption, and potential data loss. Given the critical nature of this vulnerability, organizations should prioritize patching immediately.
The vulnerability was published on October 15, 2024, and affects all versions of Starlette prior to 0.40.0. The fix has been implemented in version 0.40.0.
As of now, no known exploits or public proof of concept (PoC) exist for this vulnerability, but the potential for exploitation is high.
Vulnerability Details
Starlette is an Asynchronous Server Gateway Interface (ASGI) framework/toolkit. Prior to version 0.40.0, Starlette treats `multipart/form-data` parts without a `filename` as text form fields and buffers those in byte strings with no size limit.
This behavior allows an attacker to upload arbitrary large form fields, consuming memory resources excessively. The server may slow down significantly or even crash due to out-of-memory (OOM) errors.
The CVSS score of 8.7 indicates a high severity level, with the attack vector being network-based, low complexity, and no privileges required for exploitation. The vulnerability specifically impacts availability.
The CWE classification for this vulnerability is CWE-770, which pertains to insufficiently limiting memory consumption.
Technical Analysis
The root cause of this vulnerability lies in the handling of `multipart/form-data` requests by the Starlette framework. When a form field does not contain a filename, it is treated as a text field without size limitations, leading to unbounded memory consumption.
The attack vector is network-based, meaning that an attacker can exploit this issue remotely. The complexity of the attack is low, as it requires no special privileges or user interaction. As memory consumption increases, the server may experience degraded performance, ultimately leading to service unavailability.
Given the nature of the attack, the confidentiality and integrity impacts are deemed non-existent, while the availability impact is high due to the potential for denial of service.
Risk & Impact Analysis
The real-world risk associated with CVE-2024-47874 is significant, particularly for organizations utilizing the Starlette framework for web applications. The potential for service disruption due to this denial of service vulnerability can affect business operations, leading to financial losses and reputational damage.
Organizations should assess their exposure based on the applications they have deployed using Starlette. The blast radius of such an exploit can be extensive, particularly for services that rely heavily on form submissions.
Given the urgency of the situation, organizations should address this vulnerability in their priority patch cycle.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions of Starlette prior to 0.40.0 are affected by this vulnerability. Organizations using these versions should upgrade to the latest version to mitigate the risks.
Mitigation & Remediation
Organizations should upgrade to Starlette version 0.40.0 or later to remediate this vulnerability. If immediate patching is not feasible, consider implementing request size limits at the reverse proxy level to help mitigate the risk of service disruption.
Regular monitoring and testing of the application for vulnerabilities can also help in identifying potential weaknesses that may not yet be addressed.
For additional support and security validation, organizations can consider engaging in penetration testing services to assess their security posture.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for unusual patterns of `multipart/form-data` uploads, especially those without filenames.
Behavioral anomalies in application performance, such as sudden slowdowns or increased memory usage, should also be investigated promptly.
AppSecure Threat Intelligence Insight
CVE-2024-47874 highlights the ongoing challenges related to application security, particularly in frameworks like Starlette that handle user inputs. The capability for attackers to exploit memory allocation issues demonstrates the need for robust input validation and resource management strategies.
Security teams should prioritize reviewing their application architectures and implement best practices to prevent similar vulnerabilities in the future. Engaging in a proactive penetration testing methodology can significantly enhance organizational security.
In addition, fostering a culture of security awareness among developers and stakeholders can lead to better security practices and reduce the likelihood of vulnerabilities being introduced into the codebase.
The strategic takeaway from this incident is that organizations must remain vigilant and continuously assess their security posture against evolving threats. For further reading on application security trends and best practices, consider reviewing resources on vulnerability management programs and effective API penetration testing techniques.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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