CVE-2024-58250: Privilege Mishandling Vulnerability in pppd’s passprompt Plugin

Overview

The vulnerability in question, CVE-2024-58250, is a notable security flaw in the passprompt plugin found in the Point-to-Point Protocol Daemon (pppd) in versions of ppp before 2.5.2. This vulnerability could potentially affect a wide range of systems and devices that employ ppp for network protocol operations, primarily in UNIX-based systems. The issue at hand is crucial as it can lead to severe consequences such as full system compromise or data leakage, warranting immediate attention and mitigation.

Vulnerability Summary

CVE ID: CVE-2024-58250
Severity: Critical (9.3 CVSS Score)
Attack Vector: Network
Privileges Required: Low
User Interaction: None
Impact: Full system compromise, potential data leakage

Affected Products

Product | Affected Versions

ppp | versions before 2.5.2

How the Exploit Works

The vulnerability is centered around the mishandling of privileges in the passprompt plugin within pppd. An attacker can exploit this by sending specially crafted requests or commands to a system running the affected ppp versions. Since the passprompt plugin does not appropriately handle privileges, the attacker’s malicious commands could be executed with higher privileges than intended. This can potentially lead to a full system compromise or data leakage.

Conceptual Example Code

Below is a conceptual example of how this vulnerability could be exploited. This code simulates a malicious payload sent to a vulnerable system:

$ pppd call malicious_script

In this example, `malicious_script` is a specially crafted script designed to exploit the privilege mishandling in the passprompt plugin. When the script is called through pppd, it could execute commands with higher privileges, leading to unauthorized access or data leakage.

Mitigation Guidance

As a mitigation measure, users are advised to apply the vendor patch to update ppp to version 2.5.2 or later, which resolves the vulnerability. In cases where immediate patching is not possible, employing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as temporary mitigation to detect and prevent malicious activities exploiting this vulnerability.