CVE-2022-43551
A vulnerability exists in curl <7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP.
Published Dec 23, 2022 · updated Oct 14, 2026 · haxx curl
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.
Timeline
Detection, updates, and resolution for this record.
Dec 23, 2022 · NIST NVD
Detected
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
Oct 14, 2026 · NIST NVD
Updated
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
Affected
- cpe fedoraproject/fedora37
- cpe haxx/curlversion unspecified
- cpe netapp/active iq unified managerversion unspecified
- cpe netapp/oncommand insightversion unspecified
- cpe netapp/oncommand workflow automationversion unspecified
- cpe netapp/snapcenterversion unspecified
- cpe splunk/universal forwarderversion unspecified
Sources
- CVE.orgCVE-2022-43551
Official CVE identifier
cve.org - FIRST EPSSCVE-2022-43551
30-day exploitation probability 16.5%
first.org - NIST NVDCVE-2022-43551
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 mechanis
nvd.nist.gov