CVE-2023-38545
9.8 · CRITICALOverview
CVE-2023-38545 is a critical-severity vulnerability affecting haxx libcurl. It was published on October 18, 2023 and has a CVSS 3.1 base score of 9.8 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
This flaw makes curl overflow a heap based buffer in the SOCKS5 proxy
handshake.
When curl is asked to pass along the host name to the SOCKS5 proxy to allow
that to resolve the address instead of it getting done by curl itself, the
maximum length that host name can be is 255 bytes.
If the host name is detected to be longer, curl switches to local name
resolving and instead passes on the resolved address only. Due to this bug,
the local variable that means "let the host resolve the name" could get the
wrong value during a slow SOCKS5 handshake, and contrary to the intention,
copy the too long host name to the target buffer instead of copying just the
resolved address there.
The target buffer being a heap based buffer, and the host name coming from the
URL that curl has been told to operate with.
Remediation
Check the references section for vendor advisories and patches from haxx. Update libcurl to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| haxx | libcurl | >= 7.69.0, < 8.4.0 | Affected |
| microsoft | windows_10_1809 | >= 0, < 10.0.17763.5122 | Affected |
| microsoft | windows_10_21h2 | >= 0, < 10.0.19044.3693 | Affected |
| microsoft | windows_10_22h2 | >= 0, < 10.0.19045.3693 | Affected |
| microsoft | windows_11_21h2 | >= 0, < 10.0.22000.2600 | Affected |
| microsoft | windows_11_22h2 | >= 0, < 10.0.22621.2715 | Affected |
| microsoft | windows_11_23h2 | >= 0, < 10.0.22631.2715 | Affected |
| microsoft | windows_server_2019 | >= 0, < 10.0.17763.5122 | Affected |
| microsoft | windows_server_2022 | >= 0, < 10.0.20348.2113 | Affected |
References
Frequently Asked Questions
What is CVE-2023-38545?
CVE-2023-38545 is a critical-severity vulnerability affecting haxx libcurl. It was published on October 18, 2023 and has a CVSS 3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2023-38545?
This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2023-38545?
Check the references section for vendor advisories and patches from haxx. Update libcurl to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2023-38545?
CyberStrike's AI-powered security agents can automatically detect CVE-2023-38545 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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