CVE-2025-65037: Azure Container Apps RCE Vulnerability

CVE-2025-65037 Overview

CVE-2025-65037 is a critical code injection vulnerability affecting Microsoft Azure Container Apps. This vulnerability stems from improper control of generation of code (CWE-94), allowing an unauthorized attacker to execute arbitrary code over a network without requiring any user interaction or prior authentication.

The vulnerability represents a severe risk to cloud infrastructure deployments utilizing Azure Container Apps, as successful exploitation could lead to complete compromise of containerized workloads and potentially lateral movement within the Azure environment.

Critical Impact

This vulnerability enables unauthenticated remote code execution on Azure Container Apps, potentially compromising containerized workloads and associated cloud resources with maximum impact on confidentiality, integrity, and availability.

Affected Products

• Microsoft Azure Container Apps

Discovery Timeline

• 2025-12-18 - CVE-2025-65037 published to NVD
• 2026-01-15 - Last updated in NVD database

Technical Details for CVE-2025-65037

Vulnerability Analysis

This vulnerability is classified as a code injection flaw (CWE-94: Improper Control of Generation of Code), which occurs when an application constructs code segments using externally-influenced input without proper neutralization of special elements that could modify the intended code behavior.

In the context of Azure Container Apps, this vulnerability allows attackers to inject and execute malicious code within the container runtime environment. The network-based attack vector combined with the absence of authentication requirements makes this vulnerability particularly dangerous, as it can be exploited remotely by any attacker with network access to vulnerable Azure Container Apps instances.

The scope change indicated in the vulnerability characteristics means that successful exploitation can affect resources beyond the vulnerable component's security boundary, potentially impacting other containers, services, or Azure resources within the same environment.

Root Cause

The root cause of this vulnerability lies in improper input validation and code generation controls within Azure Container Apps. The service fails to adequately sanitize or validate user-controllable input before incorporating it into dynamically generated code segments. This allows attackers to craft malicious input that, when processed by the application, results in the execution of arbitrary code within the container environment.

Attack Vector

The attack can be conducted remotely over the network without requiring authentication or user interaction. An attacker can exploit this vulnerability by sending specially crafted requests to a vulnerable Azure Container Apps instance. The low attack complexity indicates that exploitation is straightforward and does not require specialized conditions or sophisticated techniques.

The attack flow typically involves:

1. Identifying a vulnerable Azure Container Apps deployment accessible over the network
2. Crafting malicious input containing code injection payloads
3. Submitting the payload through exposed interfaces or endpoints
4. Achieving arbitrary code execution within the container environment

Due to the sensitive nature of this vulnerability and the lack of verified public proof-of-concept code, specific exploitation details are not provided. For technical details, refer to the Microsoft Security Advisory.

Detection Methods for CVE-2025-65037

Indicators of Compromise

• Unusual outbound network connections from Azure Container Apps to unknown or suspicious external IP addresses
• Unexpected process execution or child processes spawned within container environments
• Anomalous container behavior including resource consumption spikes or unauthorized file system modifications
• Log entries indicating malformed or suspicious input patterns targeting container endpoints

Detection Strategies

• Enable Azure Container Apps diagnostic logging and stream logs to Azure Monitor or a SIEM for centralized analysis
• Implement network traffic analysis to detect unusual patterns or communications from containerized workloads
• Deploy runtime security monitoring solutions such as SentinelOne Singularity Cloud Workload Security to detect code injection attempts and anomalous container behavior
• Monitor Azure Activity Logs for unauthorized configuration changes or suspicious API calls

Monitoring Recommendations

• Configure Azure Security Center alerts for container-related security events and anomalies
• Implement continuous vulnerability scanning of container images and runtime environments
• Enable container-level monitoring with detailed logging of process execution and network activity
• Set up automated alerting for deviations from established container behavior baselines

How to Mitigate CVE-2025-65037

Immediate Actions Required

• Review the Microsoft Security Advisory for specific remediation guidance and apply any available patches or updates immediately
• Audit all Azure Container Apps deployments to identify potentially affected instances
• Implement network segmentation to limit exposure of containerized workloads
• Enable enhanced logging and monitoring across all Azure Container Apps environments

Patch Information

Microsoft has issued a security advisory for this vulnerability. Administrators should consult the official Microsoft CVE-2025-65037 Advisory for specific patch information, affected versions, and remediation steps. As this is a cloud service vulnerability, Microsoft may apply fixes server-side, but customers should verify their deployment configurations align with current security recommendations.

Workarounds

• Implement strict network access controls using Azure Virtual Networks and Network Security Groups to limit exposure of Container Apps to trusted sources only
• Enable Azure Web Application Firewall (WAF) in front of Container Apps to filter potentially malicious requests
• Apply the principle of least privilege to container workload identities and service accounts
• Consider temporary suspension of non-critical Container Apps deployments until patches are confirmed applied

# Azure CLI - Restrict network access to Container Apps environment
az containerapp env update \
  --name <environment-name> \
  --resource-group <resource-group> \
  --internal-only true

# Enable diagnostic settings for monitoring
az monitor diagnostic-settings create \
  --name "ContainerAppsSecurityLogs" \
  --resource <container-app-resource-id> \
  --logs '[{"category": "ContainerAppConsoleLogs", "enabled": true}, {"category": "ContainerAppSystemLogs", "enabled": true}]' \
  --workspace <log-analytics-workspace-id>