CVE-2024-41436: Buffer Overflow Vulnerability in ClickHouse v24.3.3.102 and its Exploitation

A new vulnerability, CVE-2024-41436, has been discovered in ClickHouse v24.3.3.102, an open-source column-oriented database management system (DBMS) used for online analytical processing (OLAP) tasks. The vulnerability is caused by a buffer overflow issue in the DB::evaluateConstantExpressionImpl component. This can lead to the potential execution of arbitrary code, allowing an attacker to compromise the affected system, resulting in a significant security risk.

Exploit Details

A buffer overflow vulnerability in ClickHouse occurs when the program attempts to store data in a fixed-size buffer but instead writes data beyond the buffer's boundaries, overwriting adjacent memory space. The issue is present in the DB::evaluateConstantExpressionImpl component of ClickHouse, which is responsible for evaluating constant expressions in SQL queries.

The following code snippet demonstrates the buffer overflow vulnerability

DB::ColumnTypePtr DB::evaluateConstantExpressionImpl(
    const ASTPtr & ast,
    const Context & context,
    size_t level)
{
    size_t size = 100; // Fixed-size buffer
    char buffer[size]; // Buffer declaration
    strcpy(buffer, ast->toString().c_str()); // Copy potentially large string into fixed-size buffer
    ...
}

In this code snippet, a fixed-size buffer is declared with a size of 100. The function then copies the string representation of an AST (Abstract Syntax Tree) object into the buffer using the strcpy() function, without properly validating the string's length. This can lead to a buffer overflow if the string is larger than the allocated buffer size, potentially allowing an attacker to gain control over the program's execution.

Original References

1. ClickHouse GitHub Repository: https://github.com/ClickHouse/ClickHouse
2. CVE-2024-41436 Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-41436
3. National Vulnerability Database (NVD) Entry: https://nvd.nist.gov/vuln/detail/CVE-2024-41436

Mitigations and Recommendations

To mitigate the risk posed by the buffer overflow vulnerability in ClickHouse v24.3.3.102, users should apply theappropriate patches provided by the software vendor, or upgrade to the latest version of ClickHouse, which contains a fix for the vulnerability.

Developers are encouraged to employ good coding practices to prevent buffer overflows, such as using safer string manipulation functions like strncpy() that take the length of the target buffer into account. In addition, it is important to validate the length of strings copied into buffers and allocate sufficient buffer size to avoid overflows.

Conclusion

The discovery of the CVE-2024-41436 buffer overflow vulnerability in ClickHouse v24.3.3.102 is a reminder of the importance of secure coding practices and keeping software up to date with the latest patches and updates. By addressing this issue promptly and following recommended security best practices, organizations and individuals using ClickHouse can continue to protect their systems and data from potential exploitation.

Timeline

Published on: 09/03/2024 19:15:14 UTC
Last modified on: 09/03/2024 20:35:15 UTC