Critical Security Update for pcs and pcs-snmp Packages: Unbounded-Parameter DoS Vulnerability
Summary
ALSA-2025:8254: Important: pcs security update. Affects pcs versions < 0.10.18-2.el8_10.5.alma.1. Fixed in 0.10.18-2.el8_10.5.alma.1. How to fix ↓
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Background
The pcs (Pacemaker/Corosync) packages provide a command-line configuration system essential for managing high-availability clusters. These packages facilitate the configuration and management of cluster resources, ensuring that services remain available even in the event of hardware or software failures. The pcs-snmp package extends this functionality by integrating SNMP (Simple Network Management Protocol) capabilities, allowing for better monitoring and management of cluster states. However, recent vulnerabilities have been identified that could potentially compromise the security and stability of systems utilizing these packages.
Vulnerability Detail
The pcs packages have been found to contain vulnerabilities that could lead to Denial of Service (DoS) attacks. Specifically, the rubygem-rack component is susceptible to an Unbounded-Parameter DoS in Rack::QueryParser (CVE-2025-46727), which allows attackers to send specially crafted requests that could overwhelm the server. Additionally, the tornado framework used in these packages is affected by a Tornado Multipart Form-Data Denial of Service vulnerability (CVE-2025-47287), which can also be exploited to disrupt service availability. These vulnerabilities can result in significant downtime and loss of service, impacting users and organizations relying on these packages for critical operations.
How To Fix
Minimum fixed version
0.10.18-2.el8_10.5.alma.1
This is the first release that contains the fix.
sudo dnf update pcsTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, you can limit access to the affected services or implement rate limiting on incoming requests to reduce the risk of exploitation until the packages are updated. This can be done by configuring your firewall or using web server settings to restrict traffic.
Conclusion
In summary, the pcs and pcs-snmp packages have critical vulnerabilities that require immediate attention. Updating to the latest patched version is essential to protect against potential Denial of Service attacks. Users should also consider temporary workarounds while preparing for the update.
See every vulnerability recorded for pcs →
FAQ
The main vulnerabilities are an Unbounded-Parameter DoS in Rack::QueryParser and a Tornado Multipart Form-Data DoS, which can lead to service disruptions.
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These vulnerabilities can lead to Denial of Service attacks, causing significant downtime and loss of service for users and organizations.
It is recommended to regularly check for updates and apply them as soon as they are available to minimize security risks.
If immediate updates are not possible, consider implementing access restrictions or rate limiting as a temporary workaround.
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