A vulnerability has been found in UltraVNC up to 1.2.2.3 (Connectivity Software) and classified as problematic. This vulnerability affects an unknown part of the component VNC Client. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. CVE summarizes:

UltraVNC revision 1207 has out-of-bounds read vulnerability in VNC client code inside TextChat module, which results in a denial of service (DoS) condition. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in revision 1208.

The bug was discovered 03/01/2019. The weakness was disclosed 03/08/2019 by Pavel Cheremushkin with Kaspersky Lab ICS CERT as KLCERT-19-014: UltraVNC Out-of-bounds Read as confirmed advisory (Website). The advisory is shared for download at ics-cert.kaspersky.com. The original advisory by Kaspersky has a very bad quality and consists of contradicting statements (e.g. summary and CVSS vectors). This vulnerability was named CVE-2019-8267 since 02/12/2019. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The advisory points out:

UltraVNC revision 1207 has out-of-bounds read vulnerability in VNC client code inside TextChat module, which results in a denial of service (DoS) condition. This attack appear to be exploitable via network connectivity. This vulnerability has been fixed in revision 1208.

The vulnerability was handled as a non-public zero-day exploit for at least 7 days. During that time the estimated underground price was around $0-$5k. The advisory illustrates:

Successful exploitation of this vulnerability could allow an attacker to cause denial of service.

Upgrading to version 1.2.2.4 eliminates this vulnerability. Applying the patch Revision 1208 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version. A possible mitigation has been published 6 days after the disclosure of the vulnerability.

Additional details are provided at us-cert.gov. The entries 131509, 131510, 131511 and 131513 are pretty similar.

Productinfo

Type

• Connectivity Software

Name

• UltraVNC

Version

• 1.0.4
• 1.0.5
• 1.0.5.1
• 1.0.8.2
• 1.0.9.5
• 1.0.9.6
• 1.0.9.6.2
• 1.1.4
• 1.1.5
• 1.1.8.0
• 1.1.8.3
• 1.1.8.4
• 1.1.8.5
• 1.1.8.6
• 1.1.8.9
• 1.1.9.0
• 1.1.9.1
• 1.1.9.3
• 1.1.9.6
• 1.2.0.1
• 1.2.0.3
• 1.2.0.4
• 1.2.0.5
• 1.2.0.6
• 1.2.0.7
• 1.2.0.9
• 1.2.1.1
• 1.2.1.2
• 1.2.1.6
• 1.2.1.7
• 1.2.2.1
• 1.2.2.2
• 1.2.2.3

License

• open-source

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

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• 🔍
• 🔍

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Threat Intelligenceinfo

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Entryinfo

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