OpenSSL server denial-of-service (CVE-2021-3449)

Advisory ID CVE Number Date discovered Severity Advisory revision
STORM-2021-008 CVE-2021-3449 03/25/2021 high v2

Vulnerability details

An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client.

Impacted products

ProductsSeverityDetail
Stormshield Endpoint Security high SES is impacted

Revisions

Version Date Description
v1  05/17/2021 Initial release
v2  05/19/2021 Updated :
  • proof-of-concept code is available
  • fixed URL for this advisory


Stormshield Endpoint Security

CVSS v3.1 Overall Score: 7.5      

Analysis

Impacted version

A SES server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. Although SES has built-in mechanisms to restart the server automatically, repeated attack may make the service unavailable.
  • SES 7.2.29 to 7.2.33.

Note: SES Evolution is not impacted by this vulnerability.

Workaround solution

Solution

There is no workaround solution.

The 7.2.34 update fixes this vulnerability.



Attack Vector Attack Complexity Privileges Required User Interaction Scope Confidentiality Impact Integrity Impact Availability impact
Adjacent Network Low None None Unchanged None None High
CVSS Base score: 6.5 CVSS Vector: (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Exploit Code Maturity Remediation Level Report Confidence
Proof of concept code Official fix Confirmed
CVSS Temporal score: 5.9 CVSS Vector: (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C)
Confidentiality Requirement Integrity Requirement Availability Requirement
Low Low High
CVSS Environmental score: 7.5 CVSS Vector: (AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C/CR:L/IR:L/AR:H/MAV:X/MAC:X/MPR:X/MUI:X/MS:X/MC:X/MI:X/MA:X)