2021-2342 | Oracle MySQL Server Optimizer denial of service

By Max On Jul 25, 2021

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4.7	$0-$5k	1.02

A vulnerability has been found in Oracle MySQL Server up to 5.7.34/8.0.25 (Database Software) and classified as critical. This vulnerability affects an unknown code of the component Optimizer. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. As an impact it is known to affect availability. CVE summarizes:

Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 5.7.34 and prior and 8.0.25 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).

The weakness was released 07/20/2021 as Oracle Critical Patch Update Advisory – July 2021. The advisory is shared for download at oracle.com. This vulnerability was named CVE-2021-2342 since 12/09/2020. The exploitation appears to be easy. The attack can be initiated remotely. The exploitation needs additional levels of successful authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/25/2021). The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

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