CVE-2023-30536 is a medium-severity vulnerability affecting the Slim Framework's slim_psr-7 component, specifically in versions prior to 1.6.1. This vulnerability arises from the improper handling of newline characters in HTTP header names and values, which can lead to malformed messages and application errors.
The CVSS score for this vulnerability is 6.5, indicating a medium risk level. Organizations using Slim Framework should be aware that the attack vector is network-based and the attack complexity is low, meaning that it could be exploited easily by an attacker without requiring any special privileges or user interaction.
Risk to organizations includes potential denial of service if a remote service's web application firewall bans the application due to the receipt of malformed requests. The issue has been patched in version 1.6.1, and organizations are advised to upgrade immediately to mitigate this risk.
As of now, there are no public exploits confirmed for this vulnerability, and it has not been included in the Known Exploited Vulnerabilities (KEV) catalog, which indicates that it is not actively exploited in the wild.
Organizations should prioritize patching immediately to safeguard their applications against this vulnerability.
Vulnerability Details
The official description of CVE-2023-30536 states that the slim/psr7 implementation allows an attacker to insert a newline character into both header names and values. This issue occurs because many servers accept \n\n as a valid termination for HTTP headers, even though the specification mandates \r\n\r\n.
The vulnerability falls under CWE-436, which pertains to improper header validation. The affected product, slim_psr-7, has been patched in version 1.6.1, which should be implemented to remediate the issue.
The CVSS 3.1 vector string for this vulnerability is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L, which helps in assessing the potential impacts on confidentiality, integrity, and availability.
Technical Analysis
The root cause of this vulnerability stems from the failure to properly validate and sanitize HTTP header inputs. Attackers may exploit this by crafting requests with malicious header names that contain newline characters, leading to unexpected application behavior.
The attack vector is network-based, allowing remote attackers to exploit this vulnerability without needing physical access or high privileges. The attack complexity is low, as it does not require any specialized skills or knowledge of the system.
No user interaction is required, making it easier for attackers to execute the attack successfully. The impacts of the vulnerability include low integrity and availability impacts, as malformed headers could lead to application errors or denial of service through web application firewalls.
Risk & Impact Analysis
Deployments using the Slim framework with slim_psr-7 are at risk as this vulnerability can lead to application errors or service disruptions. The lack of proper header validation can allow an attacker to craft requests that may bypass security controls, potentially leading to denial of service.
Organizations need to understand that the risk of exploitation is present, particularly in environments that rely on third-party services or APIs that may enforce strict input validation. As the CVSS score of 6.5 indicates a medium severity, organizations should address this issue in their priority patch cycle.
With an EPSS score of 0.00147 and a percentile of 0.351, the potential for exploitation within the next 30 days is low. However, organizations should not become complacent and must ensure that they apply the necessary patches.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerability affects all versions of slim_psr-7 prior to 1.6.1. Users are strongly advised to upgrade to this version or later to mitigate the identified risks.
Mitigation & Remediation
To remediate this vulnerability, organizations should upgrade to version 1.6.1 of slim_psr-7. There are no known workarounds for this issue, making the upgrade the only effective solution.
In addition to applying the patch, organizations should consider implementing additional security measures such as input validation and header sanitization to prevent similar vulnerabilities in the future. Regular security assessments and continuous monitoring can also help identify and mitigate potential risks.
For further guidance on securing your applications, organizations should explore application security assessment services.
Detection Guidance
Organizations should monitor logs for indicators of malformed HTTP requests that may indicate attempts to exploit this vulnerability. Behavioral anomalies in application performance could also suggest potential exploitation.
Network signatures that identify unexpected header formats should be established to help detect attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2023-30536 lies in its demonstration of how improper input validation can lead to critical vulnerabilities, particularly in components that are widely used like slim_psr-7. Security teams must recognize the potential for similar issues in other libraries and frameworks.
This vulnerability highlights the importance of thorough security audits and regular updates to dependencies. Organizations should adopt a proactive approach to identify and remediate vulnerabilities before they can be exploited.
For more information on securing your applications and understanding threat landscapes, refer to our resources on penetration testing methodology and vulnerability management program design best practices.
Additionally, organizations may consider leveraging our red teaming services to further enhance their security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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