Detection rules › Sigma

Non-Standard Nsswitch.Conf Creation - Potential CVE-2025-32463 Exploitation

Status
experimental
Severity
high
Log source
product linux, category file_event
Author
Swachchhanda Shrawn Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the creation of nsswitch.conf files in non-standard directories, which may indicate exploitation of CVE-2025-32463. This vulnerability requires an attacker to create a nsswitch.conf in a directory that will be used during sudo chroot operations. When sudo executes, it loads malicious shared libraries from user-controlled locations within the chroot environment, potentially leading to arbitrary code execution and privilege escalation.

MITRE ATT&CK coverage

TacticTechniques
Privilege EscalationT1068 Exploitation for Privilege Escalation

Event coverage

Rule body yaml

title: Non-Standard Nsswitch.Conf Creation - Potential CVE-2025-32463 Exploitation
id: 10ac0730-c24e-4f4c-81f8-b13a1ac95a1d
status: experimental
description: |
    Detects the creation of nsswitch.conf files in non-standard directories, which may indicate exploitation of CVE-2025-32463.
    This vulnerability requires an attacker to create a nsswitch.conf in a directory that will be used during sudo chroot operations.
    When sudo executes, it loads malicious shared libraries from user-controlled locations within the chroot environment,
    potentially leading to arbitrary code execution and privilege escalation.
references:
    - https://github.com/kh4sh3i/CVE-2025-32463/blob/81bb430f84fa2089224733c3ed4bfa434c197ad4/exploit.sh
author: Swachchhanda Shrawn Poudel (Nextron Systems)
date: 2025-10-02
modified: 2026-03-31
tags:
    - attack.privilege-escalation
    - attack.t1068
    - cve.2025-32463
    - detection.emerging-threats
logsource:
    category: file_event
    product: linux
detection:
    selection:
        TargetFilename|endswith: '/etc/nsswitch.conf'
    filter_main_legitimate_path:
        TargetFilename:
            - '/etc/nsswitch.conf'
            - '/usr/share/factory/etc/nsswitch.conf'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Backup locations
level: high

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_*

Stage 1: selection

selection:
    TargetFilename|endswith: '/etc/nsswitch.conf'

Stage 2: not filter_main_legitimate_path

filter_main_legitimate_path:
    TargetFilename:
        - '/etc/nsswitch.conf'
        - '/usr/share/factory/etc/nsswitch.conf'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
TargetFilenameeq/etc/nsswitch.conf
TargetFilenameeq/usr/share/factory/etc/nsswitch.conf

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
TargetFilenameends_with
  • /etc/nsswitch.conf