A use after free vulnerability exists in curl versions below 7.87.0. Curl can be asked to tunnel virtually all protocols it supports through an HTTP proxy. However, HTTP proxies can and often do deny such tunnel operations. When denied tunneling for specific protocols like SMB or TELNET, curl would use a heap-allocated struct after it had been freed in its transfer shutdown code path.
The severity of this vulnerability is classified as medium with a CVSS score of 5.9. This level of severity indicates that while exploitation may not be straightforward, it can still lead to significant availability impact. Organizations leveraging curl in their infrastructure must take this seriously as misuse could lead to service disruptions.
Currently, there is no known public exploit available for this vulnerability, and it has not been categorized as actively exploited in the wild. Nonetheless, organizations should remain vigilant and prioritize patching this vulnerability to mitigate potential risks.
Organizations should prioritize patching immediately to prevent any potential disruption to services reliant on curl.
Vulnerability Details
This vulnerability allows for a situation where curl could operate improperly due to incorrect memory management after a denial of service from an HTTP proxy. The CVSS vector string for this vulnerability is CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H, indicating that it has a network attack vector, high attack complexity, and requires no privileges or user interaction.
The affected component is curl, and this vulnerability is classified under CWE-416. The vulnerability was published on February 9, 2023, and affects all versions of curl prior to 7.87.0.
Technical Analysis
The root cause of this vulnerability lies in the handling of memory after certain operations are denied by HTTP proxies. Specifically, when curl tries to tunnel protocols such as SMB or TELNET and is denied, it incorrectly uses a previously freed memory structure, leading to potential application instability.
The attack vector for this vulnerability is network-based, meaning that an attacker could exploit it remotely without physical access to the vulnerable system. The attack complexity is rated as high, suggesting that successful exploitation may require specific conditions or configurations.
The vulnerability does not require any privileges to exploit, nor does it require user interaction. The impact on availability is high, meaning that exploitation could lead to significant service disruptions.
Risk & Impact Analysis
The real-world risk associated with CVE-2022-43552 includes potential denial of service for applications relying on curl for operations through HTTP proxies. Given that many organizations utilize curl in their software stacks, the blast radius could be extensive, impacting service availability.
Organizations should assess their infrastructure to determine the presence of affected versions of curl and prioritize remediation. Based on the CVSS score of 5.9, organizations should address this in their priority patch cycle.
With the low likelihood of active exploitation, organizations can still not afford to be complacent. Patching this vulnerability remains critical to maintaining operational integrity.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions include all versions of curl prior to 7.87.0, as well as specific versions of macOS between 13.0 and 13.3 and the Splunk Universal Forwarder versions from 8.2.0 to 8.2.12 and 9.0.0 to 9.0.6.
Mitigation & Remediation
Organizations should patch curl to the latest version, 7.87.0 or later, to mitigate this vulnerability. If immediate patching is not feasible, organizations should consider implementing network controls to restrict the use of curl in sensitive operations, particularly those involving HTTP proxies.
In addition to patching, organizations can benefit from implementing security testing practices such as penetration testing to identify similar vulnerabilities in their applications.
Detection Guidance
Organizations should monitor logs for any unusual curl activity that could indicate exploitation attempts. Additionally, behavioral anomalies in applications using curl should be investigated thoroughly to identify any signs of abuse or potential compromise.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability underscores the importance of proper memory management in software development. This incident highlights trends in vulnerabilities associated with memory misuse. Security teams should take away lessons on the necessity of rigorous testing and validation processes to avoid similar issues in their applications.
To stay informed on similar vulnerabilities, organizations can follow vulnerability management programs and best practices in the field.
Regularly updating and testing software components is essential for maintaining security resilience. For further insights, organizations should also explore penetration testing methodology to effectively identify and remediate vulnerabilities.
Organizations should also consider leveraging continuous penetration testing services to ensure ongoing protection against such vulnerabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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