MEDIUM · 5.9

CVE-2021-3449

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it...

Vulnerability Description

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a signature_algorithms_cert extension then a NULL pointer dereference will result, leading to a crash and a denial of service attack. A server is only vulnerable if it has TLSv1.2 and renegotiation enabled (which is the default configuration). OpenSSL TLS clients are not impacted by this issue. All OpenSSL 1.1.1 versions are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1k. OpenSSL 1.0.2 is not impacted by this issue. Fixed in OpenSSL 1.1.1k (Affected 1.1.1-1.1.1j).

CVSS Score

5.9

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH

Affected Products

VendorProductVersions
OpensslOpenssl>= 1.1.1, < 1.1.1k
DebianDebian Linux9.0
FreebsdFreebsd12.2
NetappActive Iq Unified Manager-
NetappCloud Volumes Ontap Mediator-
NetappE-Series Performance Analyzer-
NetappOncommand Insight-
NetappOncommand Workflow Automation-
NetappOntap Select Deploy Administration Utility-
NetappSantricity Smi-S Provider-
NetappSnapcenter-
NetappStoragegrid-
TenableLog Correlation Engine< 6.0.9
TenableNessus<= 8.13.1
TenableNessus Network Monitor5.11.0
TenableTenable.Sc>= 5.13.0, <= 5.17.0
FedoraprojectFedora34
McafeeWeb Gateway8.2.19
McafeeWeb Gateway Cloud Service8.2.19
CheckpointQuantum Security Management Firmwarer80.40

Related Weaknesses (CWE)

References

FAQ

What is CVE-2021-3449?

CVE-2021-3449 is a vulnerability with a CVSS score of 5.9 (MEDIUM). An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it...

How severe is CVE-2021-3449?

CVE-2021-3449 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2021-3449?

Check the references section above for vendor advisories and patch information. Affected products include: Openssl Openssl, Debian Debian Linux, Freebsd Freebsd, Netapp Active Iq Unified Manager, Netapp Cloud Volumes Ontap Mediator.