CVE-2025-32463: Critical Privilege Escalation Vulnerability in Sudo

Overview

CVE-2025-32463 is a critical vulnerability discovered in Sudo, a utility found in numerous Unix- and Linux-based systems that allows a system administrator to delegate limited root access to users. This flaw can enable local users to gain full root access to the system by exploiting the –chroot option. This is particularly concerning because of the pervasiveness of Sudo, its typical configuration to allow certain users to execute commands as other users, and the potential for an attacker to compromise an entire system if the vulnerability is successfully exploited.

Vulnerability Summary

CVE ID: CVE-2025-32463
Severity: Critical (9.3 CVSS Score)
Attack Vector: Local
Privileges Required: Low
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

Sudo | Before 1.9.17p1

How the Exploit Works

The exploit takes advantage of a misconfiguration in the Sudo utility. Specifically, when the –chroot option is used, Sudo uses /etc/nsswitch.conf from a user-controlled directory. An attacker can create a malicious nsswitch.conf file in their directory, then use the –chroot option to make Sudo use their malicious nsswitch.conf file. This can allow the attacker to escalate their privileges and gain root access to the system.

Conceptual Example Code

Here’s a hypothetical command sequence that demonstrates how the vulnerability might be exploited:

# Attacker creates a malicious nsswitch.conf file in their directory
echo "passwd: files" > ~/nsswitch.conf
# Attacker uses the --chroot option to make Sudo use their malicious nsswitch.conf file
sudo --chroot . /bin/bash

In this example, the attacker creates a malicious nsswitch.conf file that specifies that user authentication should be done using only local files, not network-based services. They then run a command with Sudo using the –chroot option to make Sudo use their malicious nsswitch.conf file. This effectively grants them root access to the system.

How to Mitigate

To mitigate this vulnerability, users should apply the patch provided by the vendor, which in this case is Sudo version 1.9.17p1 or later. Alternatively, users can use a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) as a temporary mitigation until the patch can be applied. However, it’s important to note that while a WAF or IDS can help detect and prevent some exploit attempts, they are not sufficient to fully protect against this vulnerability. Users should prioritize applying the vendor’s patch as soon as possible.