CVE-2023-38546

CVE-2023-38546 is a low-severity vulnerability in Haxx Libcurl with a CVSS 3.x base score of 3.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

This flaw allows an attacker to insert cookies at will into a running program using libcurl, if the specific series of conditions are met. libcurl performs transfers. In its API, an application creates "easy handles" that are the individual handles for single transfers. libcurl provides a function call that duplicates en easy handle called [curl_easy_duphandle](https://curl.se/libcurl/c/curl_easy_duphandle.html). If a transfer has cookies enabled when the handle is duplicated, the cookie-enable state is also cloned - but without cloning the actual cookies. If the source handle did not read any cookies from a specific file on disk, the cloned version of the handle would instead store the file name as `none` (using the four ASCII letters, no quotes). Subsequent use of the cloned handle that does not explicitly set a source to load cookies from would then inadvertently load cookies from a file named `none` - if such a file exists and is readable in the current directory of the program using libcurl. And if using the correct file format of course.

Frequently asked questions

What is CVE-2023-38546?
This flaw allows an attacker to insert cookies at will into a running program using libcurl, if the specific series of conditions are met. libcurl performs transfers. In its API, an application creates "easy handles" that are the individual handles for single transfers. libcurl provides a function call that duplicates en easy handle called [curl_easy_duphandle](https://curl.se/libcurl/c/curl_easy_duphandle.html). If a transfer has cookies enabled when the handle is duplicated, the cookie-enable state is also cloned - but without cloning the actual cookies. If the source handle did not read any cookies from a specific file on disk, the cloned version of the handle would instead store the file name as `none` (using the four ASCII letters, no quotes). Subsequent use of the cloned handle that does not explicitly set a source to load cookies from would then inadvertently load cookies from a file named `none` - if such a file exists and is readable in the current directory of the program using libcurl. And if using the correct file format of course.
How severe is CVE-2023-38546?
CVE-2023-38546 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2023-38546 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-38546?
CVE-2023-38546 affects Haxx Libcurl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-38546?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-38546 published?
CVE-2023-38546 was published on 2023-10-18 and last updated on 2026-06-17.

References

Affected products (1)

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