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Vulnerabilities

Vulnerability · CVE-2021-22946

A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server ( on the command line or set to or wit…

Published Sep 29, 2021 · catalog updated Oct 14, 2026 · the affected product

Check if you run it

No confirmed exploitation is on record for CVE-2021-22946. EPSS is 4.54%. Act only if a listed version of the affected product is installed.

Gaps on this record

  • No plain product name is stored. The page cannot tell you which product to check.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
4.54%
Remediation
Advisory link
Affected products
cpe debian/debian linux · cpe fedoraproject/fedora · cpe haxx/curl · cpe netapp/cloud backup · cpe netapp/clustered data ontap · cpe netapp/h300e firmware

A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server ( on the command line or set to or withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations **withoutTLS** contrary to the instructions and expectations, exposing possibly sensitive data in clear text over the network.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe debian/debian linux10.0
  • cpe debian/debian linux11.0
  • cpe debian/debian linux9.0
  • cpe fedoraproject/fedora33
  • cpe fedoraproject/fedora35
  • cpe haxx/curlversion unspecified
  • cpe netapp/cloud backupversion unspecified
  • cpe netapp/clustered data ontapversion unspecified
  • cpe netapp/h300e firmwareversion unspecified
  • cpe netapp/h300s firmwareversion unspecified
  • cpe netapp/h500s firmwareversion unspecified
  • cpe netapp/h700s firmwareversion unspecified

How to fix CVE-2021-22946

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2021-22946. EPSS is 4.54%. Act only if a listed version of the affected product is installed.

Which versions are affected?

Compare what you have installed with debian/debian linux 10.0; debian/debian linux 11.0; debian/debian linux 9.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-319: Cleartext Transmission of Sensitive Information; CWE-325. EPSS 4.54%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 29, 2021 · NIST NVD

    Detected

    A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server ( on the command line or set to or withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations **withoutTLS** contrary to the instructions

  2. Oct 14, 2026 · NIST NVD

    Updated

    A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server ( on the command line or set to or withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations **withoutTLS** contrary to the instructions

Sources

  • CVE.orgVulnerability recordCVE-2021-22946

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-22946

    30-day exploitation probability 4.5%

    first.org
  • NIST NVDVulnerability recordCVE-2021-22946

    A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server ( on the command line or set to or withlibcurl). This requirement could be bypassed

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.