| ID | Technique | Tactic |
|---|---|---|
| T1190 | Exploit Public-Facing Application | Initial Access |
Detection: Splunk Unauthenticated Log Injection Web Service Log
REMOVED DETECTION
This detection has been removed from the Splunk Threat Research content library and is no longer maintained or supported.
Reason: Detection is deprecated as the associated CVEs have been patched in the latest Splunk release.
Removed in version: 5.6.0
If you have any questions or concerns, please reach out to us at research@splunk.com.
Description
The following analytic identifies potential log injection attempts into the Splunk server via specially crafted web URLs. It detects ANSI escape codes within the uri_path field of splunkd_webx logs. This activity is significant as it can lead to log file manipulation, potentially obfuscating malicious actions or misleading analysts. If confirmed malicious, an attacker could manipulate log files to hide their tracks or execute further attacks, compromising the integrity of the logging system and making incident response more challenging.
Search
1`splunkd_webx` uri_path IN ("*\x1B*", "*\u001b*", "*\033*", "*\0x9*", "*\0x8*")
2| stats count by uri_path method host status clientip
3| `splunk_unauthenticated_log_injection_web_service_log_filter`
Data Source
| Name | Platform | Sourcetype | Source |
|---|---|---|---|
| Splunk |  Splunk |
'splunkd_ui_access' |
'splunkd_ui_access.log' |
Macros Used
| Name | Value |
|---|---|
| splunkd_webx | index=_internal sourcetype=splunk_web_access |
| splunk_unauthenticated_log_injection_web_service_log_filter | `` |
splunk_unauthenticated_log_injection_web_service_log_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
CVE
Default Configuration
This detection is configured by default in Splunk Enterprise Security to run with the following settings:
| Setting | Value |
|---|---|
| Disabled | true |
| Cron Schedule | N/A |
| Earliest Time | N/A |
| Latest Time | N/A |
| Schedule Window | N/A |
| Creates Finding (Notable) | No |
| Creates Intermediate Finding (Risk Event) | No |
Hunting detections do not generate a Finding (Notable) or Intermediate Findings (Risk Events).
Implementation
This only affects web enabled Splunk instances. The detection does require the ability to search the _internal index.
Known False Positives
This hunting search will produce false positives if ANSI escape characters are included in URLs either voluntarily or by accident. This search will not detect obfuscated ANSI characters. This is not intended to be alerted upon.
Associated Analytic Story
References
Detection Testing
| Test Type | Status | Dataset | Source | Sourcetype |
|---|---|---|---|---|
| Validation | Not Applicable | N/A | N/A | N/A |
| Unit | Not Applicable | N/A | N/A |
N/A |
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: 7