CVE-2024-41996
Description
A vulnerability was found in the Diffie-Hellman Ephemeral (DHE) Key Agreement Protocol, where a malicious client can exploit the server's public key validation process. By forcing the server to use DHE and validating the order of public keys, the client can trigger expensive server-side modular exponentiation calculations. This issue results in asymmetric resource consumption, potentially leading to a denial of service (DoS) attack by overwhelming the server with computationally intensive operations.
Statement
This vulnerability is classified with a Low severity rather than Moderate because it requires specific conditions to be exploitable. The attack depends on the server being configured to use DHE key exchange and perform public key order validation, which is not the default in many configurations. Additionally, while the attack can cause increased CPU usage, leading to a potential denial of service, it does not directly compromise the confidentiality, integrity, or availability of the data being exchanged. The impact is limited to resource exhaustion, and mitigations such as rate limiting, alternative key exchange methods, or disabling DHE can effectively reduce the attack surface, making it less impacted than issues that could lead to direct data breaches or system compromise.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base 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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity,Authentication
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The product might connect to a malicious host while believing it is a trusted host, or the product might be deceived into accepting spoofed data that appears to originate from a trusted host.
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