CVE-2022-34968 in Percona
Summary
by MITRE • 08/03/2022
An issue in the fetch_step function in Percona Server for MySQL v8.0.28-19 allows attackers to cause a Denial of Service (DoS) via a SQL query.
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Analysis
by VulDB Data Team • 08/30/2022
The vulnerability identified as CVE-2022-34968 resides within the fetch_step function of Percona Server for MySQL version 8.0.28-19, representing a critical denial of service weakness that can be exploited through carefully crafted SQL queries. This flaw operates at the database engine level, specifically targeting the query processing mechanism that handles step-based data retrieval operations. The vulnerability manifests when the fetch_step function fails to properly validate or handle certain query parameters, creating a condition where malicious input can trigger unexpected behavior in the database server's execution flow.
The technical implementation of this vulnerability involves a failure in input validation within the fetch_step function, which is responsible for managing the iterative retrieval of data during complex query execution. When an attacker submits a specially constructed SQL query that exploits this validation gap, the function enters an unstable state that can result in the database server becoming unresponsive or terminating its connection handling process. This behavior aligns with CWE-20, which describes improper input validation as a fundamental weakness that can lead to various security consequences including denial of service conditions. The vulnerability specifically impacts the server's ability to maintain consistent service availability, as the DoS condition can be triggered repeatedly with minimal resources, making it particularly dangerous in production environments.
From an operational standpoint, this vulnerability presents significant risks to database availability and system reliability. Attackers can leverage this weakness to disrupt database services without requiring elevated privileges or complex exploitation techniques, making it an attractive target for malicious actors seeking to cause service disruption. The impact extends beyond simple service interruption as database downtime can cascade into application failures, data access issues, and potential business continuity problems. The vulnerability's exploitation requires only basic SQL injection knowledge, which increases its threat surface significantly. Organizations running Percona Server for MySQL 8.0.28-19 are particularly vulnerable as this version contains the specific code path that enables the flaw. The attack vector through SQL queries means that any application or user interface that accepts user input and passes it directly to the database server could potentially serve as an entry point for exploitation.
The mitigation strategy for CVE-2022-34968 involves immediate patching of the Percona Server for MySQL installation to a version that addresses the fetch_step function validation issue. Organizations should prioritize updating their database servers to the latest stable release that includes the fix for this vulnerability. Additionally, implementing proper input validation at the application layer can provide an additional defense mechanism, though this approach is considered a temporary workaround rather than a permanent solution. Network-level protections such as database firewalls or intrusion prevention systems can help monitor and block suspicious SQL query patterns, but these measures do not address the root cause of the vulnerability. The remediation process should include thorough testing of the patched environment to ensure that the fix does not introduce regressions in existing database functionality. Security teams should also conduct vulnerability assessments to identify any other potential instances of similar validation flaws within their database infrastructure. According to ATT&CK framework tactic TA0043, this vulnerability could be categorized under the "Reconnaissance" and "Execution" phases, as attackers may first discover the vulnerability through reconnaissance activities and then execute malicious queries to trigger the DoS condition, potentially leading to broader system compromise if not properly addressed through comprehensive security measures.