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UNPWNED
CVE Radar
MediumcURL

CVE-2021-22925

curl supports the `-t` command line option, known as `CURLOPT_TELNETOPTIONS`in libcurl. This rarely used option is used to send variable=content pairs toTELNET servers.Due to flaw in the option parser for sending `NEW_ENV` variables, libcurlcould be made to pass on uninitialized data from a stack based buffer to theserver. Therefore potentially revealing sensitive internal information to theserver using a clear-text network protocol.This could happen because curl did not call and use sscanf() correctly whenparsing the string provided by the application.

CVSS Base Score
5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Exploit Probability
92%EPSS PERCENTILE0100

More exploitable than 92% of all CVEs · Top 8%

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Details
Published
2021-08-05
Last modified
2026-10-14
Affected
cURL

Data from the National Vulnerability Database (NVD), CISA KEV, and FIRST.org EPSS. This product uses the NVD API but is not endorsed or certified by the NVD. EPSS is a probability estimate, not a guarantee of exploitation.