Out-of-bounds Read in Haxx Libcurl

CVE-2019-3823

libcurl versions from 7.34.0 to before 7.64.0 are vulnerable to a heap out-of-bounds read in the code handling the end-of-response for SMTP. If the buffer passed to `smtp_endofresp()` isn't NUL terminated and contains no character ending the parsed number, and `len` is set to 5, then the `strtol()` call reads beyond the allocated buffer. The read contents will not be returned to the caller.

Vulnerability class: Buffer Overflow

EPSS: 0.043 (90.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-3823?
CVE-2019-3823 is a medium-severity vulnerability in Haxx Libcurl, classified under Out-of-bounds Read. CVSS score: 4.3/10. Published 2019-02-06.
How severe is CVE-2019-3823?
Medium severity. CVSS v3 base score is 4.3 out of 10.
Is CVE-2019-3823 known to be exploited?
6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.