CVE-2022-43551 - CVE House
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Status published Unknown CVE-2022-43551

A vulnerability exists in curl <7.87.0 HSTS check that could...

Vulnerability Description

A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. However, the HSTS mechanism could be bypassed if the host name in the given URL first uses IDN characters that get replaced to ASCII counterparts as part of the IDN conversion. Like using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop (U+002E) `.`. Then in a subsequent request, it does not detect the HSTS state and makes a clear text transfer. Because it would store the info IDN encoded but look for it IDN decoded.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

https://github.com/curl/curl
Vulnerable Versions:
Fixed in curl 7.87.0

Timeline

Official Publish: December 23rd, 2022
Last Modified: February 13th, 2026
Added to House: July 21st, 2026

CVSS Vectors

No vector data available

Weaknesses (CWE)