CVE Catalog

CVE-2021-22925

MediumCVSS 5.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Very high risk
4.93%

92th percentile - higher than 92% of all known CVEs

Summary

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

Risk Assessment

Sensitive internal information may be disclosed to a TELNET server, potentially compromising data confidentiality.

Recommendation

Update curl to a patched version or avoid using the -t option with untrusted data.

Other vulnerabilities in curl

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS