Description
The net/http package improperly accepts a bare LF as a line terminator in chunked data chunk-size lines. This can permit request smuggling if a net/http server is used in conjunction with a server that incorrectly accepts a bare LF as part of a chunk-ext.
EPSS Score:
0%
Comprehensive Technical Analysis of EUVD-2025-11855
1. Vulnerability Assessment and Severity Evaluation
The vulnerability described in EUVD-2025-11855 pertains to the net/http package in the Go standard library. Specifically, it improperly accepts a bare Line Feed (LF) as a line terminator in chunked data chunk-size lines, which can lead to request smuggling. This vulnerability is critical, with a CVSS base score of 9.1, indicating a high severity due to the potential for significant confidentiality and integrity impacts.
CVSS Vector Breakdown:
- AV:N (Network): The vulnerability is exploitable over the network.
- AC:L (Low): The attack complexity is low, meaning it does not require specialized conditions.
- PR:N (None): No privileges are required to exploit the vulnerability.
- UI:N (None): No user interaction is required.
- S:U (Unchanged): The scope of the vulnerability does not change.
- C:H (High): There is a high impact on confidentiality.
- I:H (High): There is a high impact on integrity.
- A:N (None): There is no impact on availability.
2. Potential Attack Vectors and Exploitation Methods
Request Smuggling:
- Attack Vector: An attacker can exploit this vulnerability by sending specially crafted HTTP requests that include a bare LF in the chunk-size lines. This can cause the
net/httpserver to misinterpret the request boundaries, leading to request smuggling. - Exploitation Method: The attacker can manipulate the HTTP request to bypass security controls, inject malicious payloads, or interfere with the normal operation of the server. This can result in unauthorized access to sensitive information or the execution of unauthorized actions.
3. Affected Systems and Software Versions
The vulnerability affects the following versions of the net/http package in the Go standard library:
- Versions prior to 1.23.8
- Versions between 1.24.0 and 1.24.2
Organizations using these versions of the Go standard library in their applications are at risk.
4. Recommended Mitigation Strategies
Immediate Actions:
- Update Software: Upgrade to the latest version of the Go standard library that includes the fix for this vulnerability. Specifically, upgrade to version 1.23.8 or 1.24.2 and above.
- Patch Management: Implement a robust patch management process to ensure that all software dependencies are regularly updated.
- Network Monitoring: Enhance network monitoring to detect and respond to unusual HTTP traffic patterns that may indicate request smuggling attempts.
Long-Term Strategies:
- Code Review: Conduct thorough code reviews to identify and mitigate similar vulnerabilities in other parts of the application.
- Security Training: Provide training for developers on secure coding practices and common vulnerabilities.
- Incident Response: Develop and test an incident response plan to quickly address any security incidents related to this vulnerability.
5. Impact on European Cybersecurity Landscape
The European cybersecurity landscape is highly interconnected, with many organizations relying on open-source software like the Go standard library. This vulnerability poses a significant risk to organizations across various sectors, including finance, healthcare, and government, which handle sensitive data and require high levels of security. The potential for request smuggling can lead to data breaches, financial loss, and reputational damage.
6. Technical Details for Security Professionals
Vulnerability Details:
- Root Cause: The
net/httppackage incorrectly accepts a bare LF as a line terminator in chunked data chunk-size lines, leading to misinterpretation of request boundaries. - Technical Impact: This can result in request smuggling, where an attacker can manipulate HTTP requests to bypass security controls and gain unauthorized access to sensitive information.
Detection and Response:
- Log Analysis: Analyze HTTP request logs for unusual patterns, such as requests with bare LF characters in chunk-size lines.
- Intrusion Detection Systems (IDS): Implement IDS rules to detect and alert on suspicious HTTP traffic that may indicate request smuggling attempts.
- Security Audits: Conduct regular security audits to identify and mitigate similar vulnerabilities in other parts of the application.
References:
By addressing this vulnerability promptly and implementing robust security measures, organizations can mitigate the risk of request smuggling and protect their systems from potential attacks.