Buffer overflow in Haxx Libcurl

CVE-2016-8622

The URL percent-encoding decode function in libcurl before 7.51.0 is called `curl_easy_unescape`. Internally, even if this function would be made to allocate a unscape destination buffer larger than 2GB, it would return that new length in a signed 32 bit integer variable, thus the length would get either just truncated or both truncated and turned negative. That could then lead to libcurl writing outside of its heap based buffer.

Vulnerability class: Buffer Overflow

EPSS: 0.047 (90.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2016-8622?
CVE-2016-8622 is a low-severity vulnerability in Haxx Libcurl, classified under Heap-based Buffer Overflow. CVSS score: 3.7/10. Published 2018-07-31.
How severe is CVE-2016-8622?
Low severity. CVSS v3 base score is 3.7 out of 10.
Is CVE-2016-8622 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.