CVE-2023-38039

CVE-2023-38039 is a high-severity vulnerability in Haxx Curl with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 62% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-770.

Key facts

Description

When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API. However, curl did not have a limit in how many or how large headers it would accept in a response, allowing a malicious server to stream an endless series of headers and eventually cause curl to run out of heap memory.

Frequently asked questions

What is CVE-2023-38039?
When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API. However, curl did not have a limit in how many or how large headers it would accept in a response, allowing a malicious server to stream an endless series of headers and eventually cause curl to run out of heap memory.
How severe is CVE-2023-38039?
CVE-2023-38039 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-38039 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 62% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-38039?
CVE-2023-38039 primarily affects Haxx Curl. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-38039?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-38039 published?
CVE-2023-38039 was published on 2023-09-15 and last updated on 2026-06-17.

References

Affected products (12)

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