Vulnerability Note VU#118748

POCO C++ Libraries NetSSL library fails to properly validate wildcard certificates

Original Release date: 24 Apr 2014 | Last revised: 24 Apr 2014

Overview

The POCO C++ Libraries NetSSL library fails to properly validate wildcard certificates, allowing an attacker to trick the victim application into trusting a malicious certificate.

Description

CWE-350: Reliance on Reverse DNS Resolution for a Security-Critical Action

Guenter Obiltschnig of Applied Informatics GmbH reports:

The Poco::Net::X509Certificate::verify() method in the POCO C++ Libraries NetSSL library fails to properly validate a wildcard certificate if DNS reverse mapping is broken. In case of a wildcard certificate, the class relies on DNS to obtain aliases for the host name, which are then used for matching against the wildcard domain name(s) in the certificate.

Stable release versions 1.4.6p2 and older are affected, as well as development release version 1.50 to 1.5.2.

Impact

After a successful DNS spoofing attack, the attacker may be able to trick a SSL/TLS client into successfully validating a certificate from a malicious server. However, this requires that the certificate first passes the certificate chain validation.

Solution

Apply an Update

Vendors and developers which incorporate the POCO C++ NetSSL library into their software should update to version 1.4.6p4 or later.

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
Applied Informatics GmbHAffected-17 Apr 2014
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base 6.4 AV:N/AC:L/Au:N/C:P/I:P/A:N
Temporal 4.7 E:U/RL:OF/RC:C
Environmental 1.2 CDP:ND/TD:L/CR:ND/IR:ND/AR:ND

References

Credit

Thanks to Tuomas Siren and Alexander Berezhnoy for originally discovering the vulnerability.

This document was written by Todd Lewellen.

Other Information

  • CVE IDs: CVE-2014-0350
  • Date Public: 24 Apr 2014
  • Date First Published: 24 Apr 2014
  • Date Last Updated: 24 Apr 2014
  • Document Revision: 6

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