Bucket Hijacking Attack: Critical Cloud Data Risk

Introduction: Bucket Hijacking Attack — Why It Matters

A newly disclosed cloud attack technique known as Bucket Hijacking Attack has revealed a serious weakness in how several leading cloud providers route data to storage buckets. Security researchers demonstrated that attackers could silently redirect active cloud data streams—including audit logs, telemetry, backups, and replicated data—to storage buckets under their own control without interrupting the affected cloud services.

The technique affects cloud environments that rely on globally unique bucket names, including Amazon Web Services (AWS), Google Cloud, and Microsoft Azure. Rather than exploiting software vulnerabilities, the attack abuses cloud storage naming behavior after legitimate buckets are deleted, allowing threat actors to receive sensitive enterprise data without generating native security alerts. According to Palo Alto Networks Unit 42 researchers, the Bucket Hijacking technique can silently redirect cloud data streams to attacker-controlled storage buckets.

Although researchers responsibly disclosed their findings to all three cloud providers, the discovery highlights an overlooked risk that organizations should address immediately, particularly those using automated logging, replication, and monitoring services.

What is Bucket Hijacking?

Bucket Hijacking Attack is a cloud attack technique that exploits globally unique cloud storage bucket names. The Bucket Hijacking Attack disclosure has drawn significant attention because it targets cloud storage architecture rather than software vulnerabilities. Many cloud services continue sending data to a configured bucket name instead of verifying whether the bucket still belongs to the original cloud account.

If an organization deletes a storage bucket but leaves services configured to write data to that bucket, an attacker can recreate a bucket using the exact same globally unique name within their own cloud account. Since many cloud services identify the destination only by its bucket name, they automatically resume sending data to the newly created attacker-controlled bucket.

Unlike traditional cloud attacks that require exploiting software flaws or stealing credentials, Bucket Hijacking abuses cloud resource lifecycle management and configuration oversights.

Researchers successfully demonstrated the technique against several widely used cloud services, including:

• Google Cloud Logging
• AWS S3 Replication
• AWS Kinesis Data Firehose
• Azure Monitor Diagnostic Settings

The attack worked without disrupting the affected services, making the data redirection extremely difficult to detect during normal operations.

What Caused the Incident?

The newly disclosed technique stems from a design characteristic shared by several cloud platforms rather than a vulnerability in their underlying infrastructure.

Cloud providers generally require storage bucket names to be globally unique. Once a bucket is deleted, that unique name often becomes available for reuse by another customer. If cloud services continue referencing only the bucket name instead of validating bucket ownership, data streams may unknowingly begin sending information to a completely different cloud account.

Researchers identified three primary conditions required for a successful Bucket Hijacking attack:

• The attacker obtains permissions to delete an existing storage bucket or convinces an administrator to remove it.
• The attacker quickly recreates the same bucket name within another cloud account.
• Existing cloud services continue transmitting data to the reused bucket name without verifying ownership.

This combination creates an opportunity for silent data exfiltration without malware, ransomware, or exploitation of software vulnerabilities.

Bucket Hijacking Attack: Full Technical Breakdown

Timeline of Events

• Security researchers identified risks associated with globally unique cloud storage bucket names.
• Proof-of-concept attacks were developed against multiple major cloud platforms.
• Successful demonstrations showed active cloud data streams could be redirected to attacker-controlled buckets.
• The findings were responsibly disclosed to Google Cloud, Amazon Web Services, and Microsoft Azure.
• Cloud customers were advised to review bucket deletion permissions and strengthen monitoring practices.

How the Attack Works

The Bucket Hijacking process is relatively straightforward but highly effective:

1. An attacker gains permission to delete a legitimate storage bucket.
2. The original bucket is removed.
3. The attacker immediately creates a new bucket using the identical globally unique name.
4. Existing cloud logging, monitoring, or replication services continue sending data automatically.
5. Sensitive information begins accumulating inside the attacker’s storage bucket without triggering operational failures.

Because the original cloud services continue functioning normally, administrators may never realize that their audit logs, diagnostic information, or replicated datasets are being delivered to an unauthorized destination. Security researchers believe the Bucket Hijacking Attack should encourage organizations to review cloud storage lifecycle management and automated logging configurations before attackers can exploit similar weaknesses.

What Data and Systems Could Be Affected?

Depending on the affected cloud service, attackers may gain access to:

• Cloud audit logs
• Security telemetry
• Application logs
• Diagnostic information
• Replicated storage objects
• Backup data
• Compliance monitoring records
• Infrastructure monitoring events

The exact data exposed depends entirely on which cloud services were configured to write to the compromised bucket. Organizations with centralized logging and automated replication workflows could face significantly greater exposure due to the volume and sensitivity of transmitted information.

Potential Risks & Impact

The Bucket Hijacking Attack 2026 presents a unique challenge because it targets the trust relationship between cloud services and storage buckets rather than exploiting software vulnerabilities. Since cloud services continue functioning normally after data redirection, organizations may remain unaware that sensitive information is being transmitted to an attacker-controlled bucket for an extended period.

Identity and Security Risks

Organizations relying on centralized logging and telemetry could inadvertently expose valuable security information to attackers. While the exact data varies by workload, compromised streams may include:

• Cloud audit logs
• IAM authentication events
• Security alerts
• Infrastructure metadata
• Diagnostic logs
• Application telemetry
• Replicated storage objects
• Operational monitoring data

Attackers could use this information to understand an organization’s cloud architecture, identify privileged accounts, map internal resources, or prepare more sophisticated attacks.

Business and Operational Risks

For enterprises operating critical workloads in the cloud, the consequences extend beyond data exposure.

Potential business impacts include:

• Loss of security visibility
• Exposure of sensitive operational information
• Delayed incident detection
• Compromised forensic investigations
• Leakage of proprietary business data
• Reduced trust in cloud monitoring systems

Because security teams often depend on centralized logging platforms for threat detection and compliance monitoring, redirected logs may create blind spots during active cyber incidents.

Regulatory and Compliance Risks

Many industries are required to retain accurate audit logs for regulatory compliance. If these logs are unknowingly redirected outside an organization’s control, businesses may face compliance challenges under regulations such as:

• GDPR
• HIPAA
• PCI DSS
• ISO/IEC 27001
• SOC 2
• Regional cybersecurity regulations

Even if customer data is not directly exposed, losing control over audit trails could complicate compliance audits and incident response investigations.

Official Response

The researchers behind the Bucket Hijacking technique disclosed their findings responsibly to Google Cloud, Amazon Web Services (AWS), and Microsoft Azure before publishing the research.

According to the researchers, all three cloud providers acknowledged the issue and reviewed the affected services. The attack technique does not result from a software vulnerability in the cloud platforms themselves but rather from the way certain services reference globally unique bucket names after bucket deletion.

Researchers also noted that some mitigations are already available. AWS customers can review the AWS S3 bucket security documentation to understand account-based regional bucket namespaces and secure bucket configuration, reducing the likelihood of bucket name reuse across different AWS accounts.

At the time of publication, organizations are encouraged to implement the recommended security controls rather than relying solely on cloud provider protections.

Industry Context: Why Cloud Storage Attacks Are Increasing

Cloud environments continue to become more automated every year. Organizations increasingly depend on managed services that automatically collect logs, replicate data, synchronize backups, and stream telemetry between multiple cloud resources.

While automation improves operational efficiency, it also introduces new attack surfaces.

Instead of exploiting operating systems or applications, attackers are increasingly abusing cloud identities, storage permissions, resource configurations, and automation workflows. The Bucket Hijacking Attack demonstrates that configuration weaknesses can sometimes pose greater risks than traditional software vulnerabilities, particularly in large multi-cloud environments.

Recent cloud-focused attacks have demonstrated that misconfigurations often present greater risks than software vulnerabilities themselves. Overly permissive IAM roles, exposed cloud storage, insecure APIs, and weak lifecycle management remain among the most common causes of cloud data exposure.

Readers interested in similar cloud security incidents can explore CyberNexora’s Cyber Incidents for the latest attack analysis and cybersecurity updates.

For additional defensive guidance on cloud security best practices, visit CyberNexora’s Learn & Protect for practical security tips and awareness guides.

Organizations adopting multi-cloud strategies should also establish comprehensive governance policies to monitor storage lifecycle events, identity permissions, and automated cloud workflows.

How to Protect Your Organization

Researchers recommend several defensive measures to reduce the risk of Bucket Hijacking attacks.

1. Restrict Storage Bucket Deletion Permissions

Only authorized administrators should have permission to delete cloud storage buckets. Avoid granting deletion privileges through overly permissive administrative roles.

2. Monitor Bucket Deletion Events

Continuously monitor storage bucket deletion API calls using cloud-native monitoring tools or SIEM platforms.

Security teams should investigate unexpected bucket deletions immediately.

3. Review Automated Cloud Services

Identify every service that writes logs, telemetry, backups, or replicated data to cloud storage.

Verify that destination buckets remain under organizational ownership.

4. Implement Cloud Data Perimeter Controls

Configure cloud security policies that restrict which identities, accounts, and services may access organizational storage resources.

Data perimeter controls help prevent unauthorized cross-account communication.

5. Enable AWS Account-Based S3 Namespaces

Where supported, AWS customers should enable account-regional bucket namespaces to reduce the risk of bucket name reuse across unrelated AWS accounts.

6. Conduct Regular Cloud Configuration Reviews

Periodically audit cloud storage configurations, IAM permissions, logging pipelines, and automated replication workflows.

Security posture management tools can help identify orphaned resources and misconfigured storage destinations before attackers exploit them.

7. Apply Least-Privilege Access

Review administrative roles regularly and remove unnecessary storage management permissions.

Least-privilege access significantly reduces the opportunities for attackers who compromise privileged accounts.

Indicators of Compromise (IoCs)

Unlike conventional malware or ransomware campaigns, the Bucket Hijacking Attack does not leave behind malicious binaries or obvious indicators on endpoints. Instead, organizations should monitor cloud infrastructure for unusual administrative and storage-related events.

Potential Indicators of Compromise include:

• Unexpected deletion of production cloud storage buckets.
• Creation of buckets with identical names under unfamiliar cloud accounts.
• Missing or incomplete audit logs despite services appearing operational.
• Unexpected interruptions in centralized logging or monitoring dashboards.
• Cross-account storage access attempts that were not previously authorized.
• Sudden reduction in log volume reaching SIEM or monitoring platforms.
• Changes to cloud storage IAM policies or bucket ownership.
• Unexplained failures during compliance or forensic log retrieval.

Organizations should configure alerts for storage bucket lifecycle events, IAM privilege changes, and cloud API calls associated with bucket creation and deletion.

Key Takeaways

• Bucket Hijacking Attack exploits globally unique cloud storage bucket names rather than software vulnerabilities.
• The attack can silently redirect logs, telemetry, backups, and replicated data to attacker-controlled buckets.
• Researchers demonstrated the technique against Google Cloud, AWS, and Microsoft Azure services.
• Native cloud services may continue operating normally, making the attack difficult to detect.
• Restricting bucket deletion permissions, monitoring storage lifecycle events, and implementing least-privilege access are among the most effective defenses against the Bucket Hijacking Attack.
  

Conclusion: Bucket Hijacking Attack and What Happens Next

The disclosure of Bucket Hijacking Attack highlights how cloud security risks increasingly stem from architectural design decisions and operational misconfigurations rather than traditional software flaws. As organizations continue adopting cloud-native services and automated data pipelines, seemingly minor configuration oversights can have significant security implications.

Although the attack requires specific conditions—particularly the ability to delete a legitimate storage bucket—its ability to silently redirect active cloud data streams demonstrates why cloud governance and lifecycle management are becoming critical components of enterprise cybersecurity strategies.

Security teams should review cloud storage permissions, audit logging configurations, and automated data flows to ensure sensitive information always remains within trusted organizational boundaries.

Readers interested in strengthening their cloud security posture can also explore CyberNexora’s Resources for cybersecurity tools, learning materials, and reference guides.