Detection: Cisco Secure Firewall - Veeam CVE-2023-27532 Exploitation Activity

Updated Date: 2025-04-14 ID: 7b7c2e92-f0b2-48d2-9c9b-b8de52b6b2ae Author: Nasreddine Bencherchali, Splunk, Talos NTDR Type: TTP Product: Splunk Enterprise Security

Description

This analytic detects exploitation activity of CVE-2023-27532 using Cisco Secure Firewall Intrusion Events. It leverages Cisco Secure Firewall Threat Defense IntrusionEvent logs to identify cases where Snort signature 61514 (Veeam Backup and Replication credential dump attempt) is followed within a 5-minute window by 64795 (Veeam Backup and Replication xp_cmdshell invocation attempt), which detects the use of xp_cmdshell, a common post-exploitation technique. If confirmed malicious, this behavior is highly indicative of a successful exploitation of CVE-2023-27532, followed by remote command execution or credential dumping.

 1`cisco_secure_firewall` EventType=IntrusionEvent signature_id IN (61514, 64795)
 2
 3| bin _time span=5m
 4
 5| fillnull
 6
 7| stats dc(signature_id) as unique_signature_count 
 8        values(signature_id) as signature_id 
 9        values(signature) as signature 
10        values(class_desc) as class_desc 
11        values(MitreAttackGroups) as MitreAttackGroups 
12        values(InlineResult) as InlineResult 
13        values(InlineResultReason) as InlineResultReason 
14        values(src_ip) as src_ip 
15        values(dest_port) as dest_port 
16        values(rule) as rule 
17        values(transport) as transport 
18        values(app) as app 
19        min(_time) as firstTime 
20        max(_time) as lastTime 
21        by dest_ip
22
23| where unique_signature_count = 2
24
25| `security_content_ctime(firstTime)`
26
27| `security_content_ctime(lastTime)`
28
29| `cisco_secure_firewall___veeam_cve_2023_27532_exploitation_activity_filter`

Data Source

Name Platform Sourcetype Source
Cisco Secure Firewall Threat Defense Intrusion Event N/A 'cisco:sfw:estreamer' 'not_applicable'

Macros Used

Name Value
cisco_secure_firewall sourcetype="cisco:sfw:estreamer"
cisco_secure_firewall___veeam_cve_2023_27532_exploitation_activity_filter search *
cisco_secure_firewall___veeam_cve_2023_27532_exploitation_activity_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
T1190 Exploit Public-Facing Application Initial Access
T1210 Exploitation of Remote Services Lateral Movement
T1059.001 PowerShell Execution
T1003.001 LSASS Memory Credential Access
Delivery
Exploitation
Installation
DE.CM
CIS 13

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 Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

This search requires Cisco Secure Firewall Threat Defense Logs, which includes the IntrusionEvent EventType. This search uses an input macro named cisco_secure_firewall. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Cisco Secure Firewall Threat Defense logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives. The logs are to be ingested using the Splunk Add-on for Cisco Security Cloud (https://splunkbase.splunk.com/app/7404). The intrusion access policy must also be configured.

Known False Positives

False positives should be very unlikely.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Exploitation attempt of Veeam CVE-2023-27532 on host $dest_ip$ by $src_ip$.

Risk Object Risk Object Type Risk Score Threat Objects
dest_ip system 25 signature, src_ip

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset not_applicable cisco:sfw:estreamer
Integration ✅ Passing Dataset not_applicable cisco:sfw:estreamer

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: 1