CVE-2025-6075
Description
A vulnerability in Python’s os.path.expandvars() function that can cause performance degradation. When processing specially crafted, user-controlled input with nested environment variable patterns, the function exhibits quadratic time complexity, potentially leading to excessive CPU usage and denial of service (DoS) conditions. No code execution or data exposure occurs, so the impact is limited to performance slowdown.
Statement
This vulnerability is rated Low rather than Moderate because it only causes a performance inefficiency without affecting code execution, data integrity, or confidentiality. The flaw lies in the algorithmic complexity of os.path.expandvars(), which can become quadratic when processing crafted input containing repetitive or nested environment variable references. Exploitation requires the attacker to control the input string passed to this function, which is uncommon in secure applications. Moreover, the impact is limited to increased CPU utilization and potential slowdown, not system compromise or data manipulation. Since the issue does not introduce memory corruption, privilege escalation, or information disclosure risks, its overall impact scope and exploitability are minimal, justifying a Low severity rating.
Mitigation
No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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