Vulnerability Report

CVE-2021-22946

Title: TLS bypass in curl

Information Disclosure

Proof Of Concept

No public PoC currently indexed for CVE-2021-22946.

CWE Category CWE-319
Published Date Sep 29, 2021
Modified Date Apr 16, 2026
Exploit Status Not Found
Score 7.5 CVSS v3.1
Exploit Probability (EPSS)
4.22%

Vulnerability Summary

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 (`--ssl-reqd` on the command line or`CURLOPT_USE_SSL` set to `CURLUSESSL_CONTROL` or `CURLUSESSL_ALL` 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.

Impacted Vendors

Reference Links

http://seclists.org/fulldisclosure/2022/Mar/29 https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf https://hackerone.com/reports/1334111 https://lists.debian.org/debian-lts-announce/2021/09/msg00022.html https://lists.debian.org/debian-lts-announce/2022/08/msg00017.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/ https://security.gentoo.org/glsa/202212-01 https://security.netapp.com/advisory/ntap-20211029-0003/ https://security.netapp.com/advisory/ntap-20220121-0008/ https://support.apple.com/kb/HT213183 https://www.debian.org/security/2022/dsa-5197 https://www.oracle.com/security-alerts/cpuapr2022.html https://www.oracle.com/security-alerts/cpujan2022.html https://www.oracle.com/security-alerts/cpujul2022.html https://www.oracle.com/security-alerts/cpuoct2021.html http://seclists.org/fulldisclosure/2022/Mar/29 https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf https://hackerone.com/reports/1334111 https://lists.debian.org/debian-lts-announce/2021/09/msg00022.html https://lists.debian.org/debian-lts-announce/2022/08/msg00017.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APOAK4X73EJTAPTSVT7IRVDMUWVXNWGD/ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RWLEC6YVEM2HWUBX67SDGPSY4CQB72OE/ https://security.gentoo.org/glsa/202212-01 https://security.netapp.com/advisory/ntap-20211029-0003/ https://security.netapp.com/advisory/ntap-20220121-0008/ https://support.apple.com/kb/HT213183 https://www.debian.org/security/2022/dsa-5197 https://www.oracle.com/security-alerts/cpuapr2022.html https://www.oracle.com/security-alerts/cpujan2022.html https://www.oracle.com/security-alerts/cpujul2022.html https://www.oracle.com/security-alerts/cpuoct2021.html
CVSS v3.1
Source Entity [email protected]
Severity HIGH
7.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v3.1
Source Entity 134c704f-9b21-4f2e-91b3-4a467353bcc0
Severity HIGH
7.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
5.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:N/C:P/I:N/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-22946 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Stack

No specific products linked.