Description
Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized attacker to bypass a security feature over a network.
EPSS Score:
0%
Comprehensive Technical Analysis of EUVD-2025-34426
1. Vulnerability Assessment and Severity Evaluation
The vulnerability identified as EUVD-2025-34426, also known as CVE-2025-55315, involves an inconsistent interpretation of HTTP requests, commonly referred to as 'HTTP request/response smuggling,' in ASP.NET Core. This flaw allows an authorized attacker to bypass a security feature over a network. The CVSS (Common Vulnerability Scoring System) base score of 9.9 indicates a critical severity level. The scoring vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L/E:U/RL:O/RC:C breaks down as follows:
- Attack Vector (AV): Network (N) - The vulnerability is exploitable over the network.
- Attack Complexity (AC): Low (L) - The attack requires minimal complexity.
- Privileges Required (PR): Low (L) - The attacker needs low-level privileges.
- User Interaction (UI): None (N) - No user interaction is required.
- Scope (S): Changed (C) - The vulnerability impacts a different security scope.
- Confidentiality (C): High (H) - There is a high impact on confidentiality.
- Integrity (I): High (H) - There is a high impact on integrity.
- Availability (A): Low (L) - There is a low impact on availability.
- Exploit Code Maturity (E): Unproven (U) - No exploit code is available.
- Remediation Level (RL): Official-Fix (O) - An official fix is available.
- Report Confidence (RC): Confirmed (C) - The vulnerability has been confirmed.
2. Potential Attack Vectors and Exploitation Methods
The primary attack vector for this vulnerability is through crafted HTTP requests that exploit the inconsistent interpretation of HTTP request/response handling in ASP.NET Core. An attacker could:
- Smuggle Requests: By manipulating HTTP headers, an attacker can smuggle requests past front-end proxies or load balancers, leading to unauthorized access or data manipulation.
- Bypass Security Controls: The attacker can bypass security features such as authentication, authorization, or input validation mechanisms.
- Exfiltrate Data: By exploiting the vulnerability, an attacker could exfiltrate sensitive data from the application.
3. Affected Systems and Software Versions
The vulnerability affects multiple versions of ASP.NET Core and Microsoft Visual Studio:
- ASP.NET Core 9.0: Versions 9.0 to 9.0.10
- ASP.NET Core 8.0: Versions 8.0 to 8.0.21
- ASP.NET Core 2.3: Versions 2.3 to 2.3.6
- Microsoft Visual Studio 2022 version 17.12: Versions 17.12.0 to 17.12.13
- Microsoft Visual Studio 2022 version 17.10: Versions 17.10.0 to 17.10.20
- Microsoft Visual Studio 2022 version 17.14: Versions 17.14.0 to 17.14.17
4. Recommended Mitigation Strategies
To mitigate this vulnerability, the following strategies are recommended:
- Apply Patches: Immediately apply the official patches provided by Microsoft for the affected versions of ASP.NET Core and Visual Studio.
- Update Software: Ensure that all affected systems are updated to the latest versions that address this vulnerability.
- Network Segmentation: Implement network segmentation to limit the spread of potential attacks.
- Monitoring and Logging: Enhance monitoring and logging to detect any unusual HTTP request patterns that may indicate an exploitation attempt.
- Web Application Firewalls (WAF): Deploy WAFs to filter out malicious HTTP requests and protect against request smuggling.
5. Impact on European Cybersecurity Landscape
The impact of this vulnerability on the European cybersecurity landscape is significant due to the widespread use of ASP.NET Core and Visual Studio in enterprise environments. Organizations across various sectors, including finance, healthcare, and government, could be affected. The high severity score and the potential for data breaches and unauthorized access make this vulnerability a critical concern for European cybersecurity authorities and practitioners.
6. Technical Details for Security Professionals
For security professionals, the following technical details are pertinent:
- Detection: Implement intrusion detection systems (IDS) and intrusion prevention systems (IPS) to detect and block malicious HTTP requests.
- Configuration: Ensure that HTTP headers are properly sanitized and validated to prevent request smuggling.
- Testing: Conduct thorough penetration testing and vulnerability assessments to identify and remediate any instances of this vulnerability.
- Incident Response: Develop and maintain an incident response plan that includes steps for identifying, containing, and remediating this type of vulnerability.
References
By following these recommendations and staying vigilant, organizations can effectively mitigate the risks associated with EUVD-2025-34426 and protect their systems from potential exploitation.