Detection: Splunk Sensitive Information Disclosure in DEBUG Logging Channels

Updated Date: 2024-10-17 ID: 93dc7182-c5da-4085-82ec-401abf33d623 Author: Rod Soto, Eric McGinnis, Splunk Type: Hunting Product: Splunk Enterprise Security

Description

In Splunk versions 9.3, 9.2, 9.1, 9.1.5 Applications which have been enabled with logging level DEBUG may write sensitive information such as keys, tokens, or other sensitive strings into the internal index.

1`splunkd` log_level="DEBUG" AND component IN ("REST_Calls", "AdminManager", "JSONWebToken")
2
3| stats count min(_time) as firstTime max(_time) as lastTime by host splunk_server log_level component event_message
4
5| `security_content_ctime(firstTime)`
6
7| `security_content_ctime(lastTime)`
8
9| `splunk_sensitive_information_disclosure_in_debug_logging_channels_filter`

Data Source

Name Platform Sourcetype Source
Splunk Splunk icon Splunk 'splunkd_ui_access' 'splunkd_ui_access.log'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
splunk_sensitive_information_disclosure_in_debug_logging_channels_filter search *
splunk_sensitive_information_disclosure_in_debug_logging_channels_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1552 Unsecured Credentials Credential Access
KillChainPhase.EXPLOITAITON
NistCategory.DE_AE
Cis18Value.CIS_10
Volt Typhoon

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Risk Event False
This configuration file applies to all detections of type hunting.

Implementation

Requires access to _internal index. It is recommended to inventory and modify the search for specific apps that may have DEBUG logging enabled.

Known False Positives

There will be false positives as not every message to the DEBUG log will expose sensitive information, such as keys or other secrets.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Possible sensitive credential information found via DEBUG logging in component $component$ at $host$ _internal index 45 50 90
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset /opt/splunk/var/log/splunk/splunkd.log splunkd
Integration ✅ Passing Dataset /opt/splunk/var/log/splunk/splunkd.log splunkd

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 2