CVE-2023-22943 in Add-on Builder
Summary
by MITRE • 02/14/2023
In Splunk Add-on Builder (AoB) versions below 4.1.2 and the Splunk CloudConnect SDK versions below 3.1.3, requests to third-party APIs through the REST API Modular Input incorrectly revert to using HTTP to connect after a failure to connect over HTTPS occurs. The vulnerability affects AoB and apps that AoB generates when using the REST API Modular Input functionality through its user interface. The vulnerability also potentially affects third-party apps and add-ons that call the *cloudconnectlib.splunktacollectorlib.cloud_connect_mod_input* Python class directly.
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Analysis
by VulDB Data Team • 03/15/2023
The vulnerability identified as CVE-2023-22943 represents a critical security flaw in Splunk Add-on Builder and Splunk CloudConnect SDK components that directly impacts network communication security protocols. This issue affects versions prior to 4.1.2 for AoB and 3.1.3 for the CloudConnect SDK, creating a dangerous fallback mechanism that compromises secure communications. The vulnerability specifically targets the REST API Modular Input functionality within Splunk's ecosystem, where applications that utilize this feature are susceptible to insecure network connections. The flaw manifests when the system attempts to establish HTTPS connections to third-party APIs but fails, subsequently reverting to unencrypted HTTP connections without proper security validation or user notification.
The technical implementation of this vulnerability stems from improper error handling within the CloudConnect SDK's modular input processing mechanism. When an initial HTTPS connection attempt fails, the system automatically falls back to HTTP without verifying whether the fallback is appropriate or secure for the target endpoint. This behavior creates a man-in-the-middle attack surface where sensitive data transmitted between Splunk and third-party APIs could be intercepted, modified, or monitored by malicious actors. The vulnerability is particularly concerning because it operates transparently to administrators and end users, making detection difficult and allowing potentially compromised data flows to persist undetected. The issue affects not only the core Splunk Add-on Builder functionality but also third-party applications that directly utilize the cloudconnectlib.splunktacollectorlib.cloud_connect_mod_input Python class, extending the potential attack surface significantly.
From an operational impact perspective, this vulnerability compromises the confidentiality and integrity of data flowing through Splunk's modular input mechanisms, particularly when integrating with external APIs and services. Organizations relying on Splunk for security monitoring, log analysis, and compliance reporting face increased risk of data exposure during API communications, potentially leading to unauthorized access to sensitive operational data. The vulnerability creates a persistent security gap that could allow attackers to intercept authentication tokens, API keys, or other sensitive information transmitted through the affected pathways. Additionally, the automatic fallback behavior may mask underlying network connectivity issues, making it difficult for security teams to identify and remediate the root cause of connection failures while simultaneously introducing new attack vectors.
Organizations should immediately implement mitigations including upgrading to the patched versions of Splunk Add-on Builder (4.1.2) and CloudConnect SDK (3.1.3) to eliminate the insecure fallback mechanism. Network administrators should also implement monitoring solutions to detect unusual HTTP traffic patterns that may indicate the vulnerability being exploited. Security teams should conduct comprehensive assessments of all Splunk environments to identify applications that utilize the affected modular input functionality and ensure proper network segmentation to limit potential attack impact. The vulnerability aligns with CWE-310, which addresses cryptographic issues, and maps to ATT&CK technique T1071.004 for application layer protocol manipulation, highlighting the need for both defensive measures and continuous monitoring of network communications for signs of unauthorized fallback behavior.