Executive Summary

This Alert is flagged as TOP 25 Common Weakness Enumeration from CWE/SANS. For more information, you can read this.
Title OpenSSL 3.0.0 to 3.0.6 decodes some punycode email addresses in X.509 certificates improperly
Name VU#794340 First vendor Publication 2022-11-01
Vendor VU-CERT Last vendor Modification 2023-01-24
Severity (Vendor) N/A Revision M

Security-Database Scoring CVSS v3

Cvss vector : CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Overall CVSS Score 7.5
Base Score 7.5 Environmental Score 7.5
impact SubScore 3.6 Temporal Score 7.5
Exploitabality Sub Score 3.9
Attack Vector Network Attack Complexity Low
Privileges Required None User Interaction None
Scope Unchanged Confidentiality Impact None
Integrity Impact None Availability Impact High
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector :
Cvss Base Score N/A Attack Range N/A
Cvss Impact Score N/A Attack Complexity N/A
Cvss Expoit Score N/A Authentication N/A
Calculate full CVSS 2.0 Vectors scores



Two buffer overflow vulnerabilities were discovered in OpenSSL versions 3.0.0 through 3.0.6. These vulnerabilities were introduced in version 3.0.0 with the inclusion of support for punycode email address parsing for X.509 certificates. OpenSSL's assessment of the severity of the vulnerabilities has reduced from CRITICAL to HIGH, and OpenSSL 3.0.7 addresses the issues.


Two buffer overflows have been reported in the OpenSSL 3.0.x branch prior to version 3.0.7 that, when exploited, may lead to denial of services or, in some cases, remote code execution in the vulnerable target environment. OpenSSL client and server implementations that use the vulnerable libraries are affected. The server implementation also requires that TLS client authentication is enabled in order to attack, and potentially exploit, a vulnerable target. OpenSSL provides details:

* Fixed two buffer overflows in punycode decoding functions.

A buffer overrun can be triggered in X.509 certificate verification,
specifically in name constraint checking. Note that this occurs after
certificate chain signature verification and requires either a CA to
have signed the malicious certificate or for the application to continue
certificate verification despite failure to construct a path to a trusted

In a TLS client, this can be triggered by connecting to a malicious
server. In a TLS server, this can be triggered if the server requests
client authentication and a malicious client connects.

An attacker can craft a malicious email address to overflow
an arbitrary number of bytes containing the `.` character (decimal 46)
on the stack. This buffer overflow could result in a crash (causing a
denial of service).

An attacker can craft a malicious email address to overflow four
attacker-controlled bytes on the stack. This buffer overflow could
result in a crash (causing a denial of service) or potentially remote code
execution depending on stack layout for any given platform/compiler.

OpenSSL versions 1.1.1 and 1.0.2 are not affected.

CERT/CC is unaware of any exploitation of this vulnerability at this time.


Successful exploitation could lead to denial of service or remote execution of arbitrary code in the target environment.


Any services depending on versions of OpenSSL 3.0.x prior to OpenSSL 3.0.7 should be upgraded to version 3.0.7 or later. Operators may also consider temporarily disabling TLS client authentication until applying an update.


Thanks to OpenSSL for coordinating and remediating the vulnerability. Polar Bear is credited as having discovered CVE--2022-3602. Viktor Dukhovni is reported as the source of CVE-2022-3786.

This document was written by Kevin Stephens, Eric Hatleback, Vijay Sarvepalli, and Jeffrey S. Havrilla.

Original Source

Url : https://kb.cert.org/vuls/id/794340

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') (CWE/SANS Top 25)

CPE : Common Platform Enumeration

Application 1
Application 214
Application 410
Os 4

Alert History

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Date Informations
2023-01-24 17:22:10
  • Multiple Updates
2023-01-10 17:22:05
  • Multiple Updates
2022-12-14 21:22:03
  • Multiple Updates
2022-12-09 21:22:02
  • Multiple Updates
2022-12-07 21:22:00
  • Multiple Updates
2022-12-07 00:22:03
  • Multiple Updates
2022-12-01 17:22:13
  • Multiple Updates
2022-11-28 17:22:02
  • Multiple Updates
2022-11-21 17:22:05
  • Multiple Updates
2022-11-19 09:22:06
  • Multiple Updates
2022-11-17 00:22:03
  • Multiple Updates
2022-11-11 05:22:02
  • Multiple Updates
2022-11-09 05:22:03
  • Multiple Updates
2022-11-02 21:37:47
  • Multiple Updates
2022-11-02 05:22:08
  • Multiple Updates
2022-11-02 00:21:59
  • First insertion