ALSA-2025:21036: Cockpit HA Cluster Security Update

Nov 18, 2025 by Alex Johnson 52 views

This article discusses the important security update ALSA-2025:21036 for cockpit-ha-cluster-0.12.1-1.el10_1.1, focusing on the vulnerabilities addressed and the impact on AlmaLinux systems. This security update is crucial for maintaining the stability and integrity of systems utilizing the Pacemaker and Corosync utilities. We'll break down the specifics of the update, the Common Vulnerabilities and Exposures (CVEs) it addresses, and the steps you should take to ensure your systems are protected.

Understanding the Update

The update centers around the pcs packages, which provide a command-line configuration system for Pacemaker and Corosync. These utilities are fundamental in creating and managing high-availability clusters. The security vulnerabilities identified in these packages could potentially be exploited, leading to denial-of-service (DoS) attacks and other security breaches. Therefore, applying this update is a critical step in safeguarding your infrastructure.

Key Components Affected

The following packages are affected by this update:

cockpit-ha-cluster-0.12.1-1.el10_1.1.noarch
pcs-0.12.1-1.el10_1.1.x86_64
pcs-snmp-0.12.1-1.el10_1.1.x86_64
pcs-0.12.1-1.el10_1.1.s390x
pcs-snmp-0.12.1-1.el10_1.1.s390x
pcs-0.12.1-1.el10_1.1.ppc64le
pcs-snmp-0.12.1-1.el10_1.1.ppc64le
pcs-0.12.1-1.el10_1.1.x86_64_v2
`pcs-snmp-0.12.1-1.el10_1.1.x86_64_v2

It's essential to ensure that all instances of these packages are updated to mitigate the identified risks. The cockpit-ha-cluster package, in particular, integrates with the Cockpit web console to provide a user-friendly interface for managing high-availability clusters. Securing this component is vital for preventing unauthorized access and control.

Detailed Security Fixes

This security update addresses several vulnerabilities in the rack and rubygem-rack components. Let's delve into the specifics of each fix:

1. CVE-2025-59830: Rack QueryParser Unsafe Default

This vulnerability stems from an unsafe default in Rack's QueryParser. It allows an attacker to bypass the params_limit by using semicolon-separated parameters. This could lead to a denial-of-service (DoS) attack by overwhelming the system with an excessive number of parameters. The impact of this vulnerability is significant, as it can disrupt the availability of critical services.

Technical Explanation: The Rack::QueryParser is responsible for parsing query parameters in HTTP requests. The default configuration had a flaw that allowed attackers to send a large number of parameters, bypassing the intended limits and consuming excessive server resources. This can lead to memory exhaustion and service disruption.
Mitigation: This update ensures that the QueryParser correctly enforces the params_limit, preventing attackers from exploiting this vulnerability.

2. CVE-2025-61770: Rack Unbounded Multipart Preamble Buffering

This vulnerability involves Rack's unbounded buffering of the multipart preamble, which can lead to a DoS attack through memory exhaustion. The multipart preamble is the initial part of a multipart HTTP request, and if not properly managed, it can be exploited to consume excessive memory.

Technical Explanation: Rack's multipart parser did not have proper limits on the size of the preamble it would buffer. An attacker could send a request with an extremely large preamble, causing the server to allocate excessive memory and potentially crash.
Mitigation: The fix implemented in this update includes limiting the size of the multipart preamble buffer, preventing memory exhaustion attacks.

3. CVE-2025-61771: Rack Multipart Parser Buffers Large Non-File Fields

This vulnerability is related to how Rack's multipart parser handles large non-file fields. The parser buffers these fields entirely in memory, which can lead to a DoS attack through memory exhaustion. The non-file fields in a multipart request, if excessively large, can overwhelm the server's resources.

Technical Explanation: The multipart parser in Rack was designed to handle both file and non-file data. However, it buffered large non-file fields entirely in memory, which could be exploited by sending requests with oversized fields, leading to memory exhaustion and service disruption.
Mitigation: The update includes changes to the multipart parser to limit the amount of memory used for buffering non-file fields, mitigating the risk of memory exhaustion attacks.

4. CVE-2025-61772: Rack Memory Exhaustion Denial of Service

This vulnerability is a general Rack memory exhaustion DoS issue. It highlights the potential for attackers to exhaust server memory resources by sending crafted requests. This general vulnerability underscores the importance of robust memory management in web applications.

Technical Explanation: This CVE covers a range of potential memory exhaustion issues in Rack. By sending specific types of requests, an attacker could cause the server to allocate excessive memory, leading to a denial of service.
Mitigation: The update includes various improvements to memory management within Rack, reducing the likelihood of memory exhaustion attacks.

5. CVE-2025-61919: rubygem-rack Unbounded Read in `Rack::Request` Form Parsing

This vulnerability involves an unbounded read in the Rack::Request form parsing, which can lead to memory exhaustion. The _Rack::Request_ class is responsible for handling HTTP requests, and a flaw in its form parsing could be exploited to consume excessive memory.

Technical Explanation: The form parsing logic in Rack::Request had a vulnerability that allowed an attacker to send a specially crafted request that would cause the server to read an unbounded amount of data, leading to memory exhaustion.
Mitigation: The update includes fixes to the form parsing logic in Rack::Request to prevent unbounded reads and mitigate the risk of memory exhaustion attacks.

Impact and Severity

The severity of these vulnerabilities is marked as Important, indicating a significant risk to systems that have not applied the update. The potential for DoS attacks and memory exhaustion can disrupt critical services and compromise system availability. It's imperative to address these issues promptly to maintain a secure and stable environment.

Understanding the Risks

Denial of Service (DoS): Attackers can exploit these vulnerabilities to overwhelm the server with requests, causing it to crash or become unresponsive.
Memory Exhaustion: The vulnerabilities can lead to excessive memory consumption, impacting system performance and potentially causing crashes.
Data Corruption: Although not explicitly mentioned, memory exhaustion can sometimes lead to data corruption or other unpredictable behavior.

Mitigation Steps

To mitigate these vulnerabilities, it is crucial to update the affected packages on your AlmaLinux systems. The update process typically involves using the package manager (yum or dnf) to install the latest versions of the affected packages.

Step-by-Step Guide to Applying the Update

Identify Affected Systems: Determine which systems are running the affected packages (cockpit-ha-cluster, pcs, and pcs-snmp).
Backup Your System: Before applying any updates, it's always a good practice to back up your system to prevent data loss in case of unforeseen issues.
Update the Packages: Use the following command to update the packages:
```
sudo dnf update
```
This command will update all packages on your system, including the affected ones. Alternatively, you can update specific packages using:
```
sudo dnf update cockpit-ha-cluster pcs pcs-snmp
```
Verify the Update: After the update is complete, verify that the correct versions of the packages are installed. You can use the following command:
```
rpm -q cockpit-ha-cluster pcs pcs-snmp
```
Ensure that the versions listed match the updated versions mentioned in the security advisory.
Reboot if Necessary: In some cases, a reboot may be required for the changes to take effect. Follow the instructions provided by the update process.
Monitor Your Systems: After applying the update, monitor your systems for any unexpected behavior. Check system logs for errors or warnings.

Conclusion

The ALSA-2025:21036 security update is a critical patch for cockpit-ha-cluster and related packages, addressing several important vulnerabilities that could lead to denial-of-service attacks and memory exhaustion. By promptly applying this update, you can significantly enhance the security and stability of your AlmaLinux systems. Remember to follow the mitigation steps outlined in this article to ensure a smooth and effective update process. Staying proactive with security updates is a fundamental aspect of maintaining a robust and secure IT infrastructure.

For further information on security best practices and threat mitigation, visit The Center for Internet Security (CIS).