FERRAMENTAS LINUX: Fedora 42 Security Advisory: Critical Vulnerabilities in Golang Cloud SQL Proxy (CVE-2025-47910, CVE-2025-47906, CVE-2025-58189, CVE-2025-61723, CVE-2025-58185, CVE-2025-58188)

Fedora 42 issues critical security update for golang-cloudsql-proxy (FEDORA-2025-582e97b7b4), patching six high-severity CVEs including CVE-2025-47910 & CVE-2025-47906. Learn the risks of cross-origin bypass, RCE, & DoS vulnerabilities in the Cloud SQL Proxy and get step-by-step instructions to secure your cloud database connections immediately.

The Cloud Database Security Imperative

Is your cloud database truly secure? In the contemporary digital landscape, where data is the most valuable asset, ensuring the integrity and confidentiality of database connections is paramount.

A single vulnerability in a critical component like a connection proxy can serve as a gateway for sophisticated cyber-attacks, leading to catastrophic data breaches.

The recent Fedora 42 security advisory (FEDORA-2025-582e97b7b4) underscores this very threat, announcing the rebuilding of the golang-github-googlecloudplatform-cloudsql-proxy package to address six critical CVEs.

This article provides a comprehensive, authoritative analysis of these vulnerabilities, their potential impact on your cloud infrastructure, and the essential steps for remediation. By understanding and acting on this information, you can safeguard your systems against these specific threats and reinforce your overall cloud security posture.

What is the Cloud SQL Proxy and Why is it Important?

The Cloud SQL Proxy is an official, open-source client and Go library from Google Cloud Platform that provides secure access to Cloud SQL databases without the need for manual IP whitelisting or SSL certificate management.

It operates by establishing a secure tunnel between your application environment and your Cloud SQL instance, creating local Unix or TCP sockets that proxy connections. This architecture offers several key security and operational benefits:

Enhanced Security: It enforces Identity and Access Management (IAM)-based authentication, moving beyond traditional network-level controls.

Simplified Connectivity: It eliminates the complexity of managing static IP addresses and SSL certificates, facilitating easier scaling and maintenance.

Go Library Integration: For developers, it provides a native Go library (cloudsql-proxy) for programmatically managing secure database connections within applications.

Given its role as a gatekeeper to sensitive database resources, any vulnerability within the Cloud SQL Proxy is of high severity. A compromised proxy can lead to unauthorized data access, credential theft, or denial of service.

Detailed Breakdown of the Security Vulnerabilities

The Fedora 42 update addresses multiple vulnerabilities across different components of the Go standard library used by the proxy. Each CVE represents a distinct attack vector that could be exploited to compromise the proxy's security guarantees.

CVE-2025-47910: Cross-Origin Protection Bypass in net/http

This vulnerability involves a bypass in the cross-origin protection mechanisms within Go's net/http package. An attacker could craft malicious HTTP requests that evade intended security filters, potentially leading to cross-site request forgery (CSRF) or other client-side attacks against applications using the proxy's HTTP endpoints.

CVE-2025-47906: Unexpected Paths Returned from LookPath in os/exec

A flaw in the os/exec package's LookPath function could cause it to return unexpected and potentially dangerous file paths. If the proxy uses this function to locate binaries for execution, an attacker could manipulate the environment to cause the proxy to execute a malicious binary, leading to remote code execution (RCE).

CVE-2025-58189: ALPN Negotiation Error Leaks Attacker-Controlled Information

In the crypto/tls package, an error during Application-Layer Protocol Negotiation (ALPN) could inadvertently include attacker-controlled information in error messages. This information leakage could reveal internal state details, aiding an attacker in refining further exploits against the TLS handshake process.

CVE-2025-61723: Quadratic Complexity in PEM Parsing

The encoding/pem package was found to have a parsing inefficiency where certain invalid inputs could trigger quadratic time complexity during decoding. A malicious actor could send a specially crafted PEM block (like a certificate) to the proxy, causing a CPU exhaustion denial-of-service (DoS) attack that cripples performance.

CVE-2025-58185: Memory Exhaustion in ASN.1 Parsing

A vulnerability in the encoding/asn1 package allows a malicious DER (Distinguished Encoding Rules) payload to cause excessive memory allocation during parsing. Similar to CVE-2025-61723, this is a resource exhaustion attack where an attacker could send a malicious certificate, causing the proxy process to consume all available memory and crash.

CVE-2025-58188: Panic in DSA Certificate Validation

A flaw in the crypto/x509 package can trigger a panic (a unrecoverable runtime error in Go) when validating certificates that contain DSA (Digital Signature Algorithm) public keys. Sending such a certificate to the proxy would cause it to crash, resulting in a denial-of-service condition for all database connections relying on it.

Impact Assessment: Risks to Your Cloud Database Infrastructure

The collective impact of these vulnerabilities is severe, affecting the core security pillars of confidentiality, integrity, and availability (CIA triad).

Data Breach & Unauthorized Access: CVE-2025-47910 and CVE-2025-47906 could be chained to bypass authentication/authorization or execute arbitrary code, potentially granting attackers direct access to your Cloud SQL databases.

Service Disruption & Downtime: CVE-2025-61723, CVE-2025-58185, and CVE-2025-58188 are all DoS vectors. Exploitation would render the proxy inoperable, severing all application-to-database connectivity and causing significant operational downtime.

Information Disclosure: CVE-2025-58189 allows for the leakage of sensitive internal data, which can be used for reconnaissance in a multi-stage attack.
Organizations using the affected golang-cloudsql-proxy package (version prior to 1.31.2-9.fc42 on Fedora 42) are at immediate risk and must prioritize remediation.

Remediation: How to Apply the Fedora 42 Security Update

The remediation path is straightforward but urgent. Fedora has released the patched version 1.31.2-9.fc42. To secure your system, execute the following command with root privileges:

sudo dnf upgrade --advisory FEDORA-2025-582e97b7b4

Alternatively, you can update all packages on your system, which will include this fix:

sudo dnf update

Verification Step: After the update, confirm the installed version:

rpm -q golang-github-googlecloudplatform-cloudsql-proxy

The output should show golang-github-googlecloudplatform-cloudsql-proxy-1.31.2-9.fc42.

Best Practices for Securing Cloud Database Connections

Beyond applying this critical patch, adhering to robust cloud security principles is essential for defense-in-depth.

Principle of Least Privilege: Configure IAM roles for the Cloud SQL Proxy with the minimum permissions necessary for your applications to function.
Comprehensive Monitoring & Logging: Enable Cloud Audit Logs and integrate proxy logs with a Security Information and Event Management (SIEM) system to detect anomalous access patterns.
Regular Dependency Scanning: Implement a Software Composition Analysis (SCA) tool to automatically identify and alert on vulnerable dependencies in your codebase, including Go modules.
Network Security Layering: While the proxy reduces reliance on network controls, consider combining it with VPC Service Controls and private IP to create multiple security perimeters.
Automated Patch Management: Establish a rigorous and automated process for applying security updates to operating systems and critical dependencies like the Cloud SQL Proxy across all environments (development, staging, production).

Conclusion: Proactive Security in the Cloud Era

The Fedora 42 advisory for the Golang Cloud SQL Proxy is a potent reminder that the security of cloud infrastructure is a continuous process, not a one-time setup.

The six patched CVEs—spanning cross-origin bypass, path manipulation, information leakage, and resource exhaustion—demonstrate the multifaceted nature of modern threats.

By promptly applying the provided update (FEDORA-2025-582e97b7b4) and embedding the security best practices outlined above into your operational workflow, you transform from a reactive target into a proactive defender. In cloud security, vigilance and timely action are the most effective tools for protecting your critical data assets.

Frequently Asked Questions (FAQ)

Q1: I'm not using Fedora 42. Am I affected by these vulnerabilities?

A1: The vulnerabilities reside in the Go standard library and affect the cloudsql-proxy project itself. While this advisory is for Fedora 42, users of the proxy on any platform (other Linux distributions, Windows, macOS) or via direct Go module installation should check the upstream Google Cloud Platform repository for security patches and update to the latest secure version.

Q2: What is the severity score (CVSS) for these CVEs?

A2: The Fedora advisory does not list CVSS scores. For detailed severity assessments, refer to the (NVD) entries for each CVE (e.g., CVE-2025-47910). Typically, vulnerabilities allowing RCE (like CVE-2025-47906) or critical DoS (like CVE-2025-58185) are rated as High or Critical.

Q3: Can these vulnerabilities be exploited remotely?

A3: Yes, most can be exploited remotely. An attacker needs to be able to send network traffic to the proxy's listening socket (for TLS, HTTP, or connection initiation attacks) or influence its execution environment (for path manipulation).

Q4: Where can I find the official source code and changelog for the Cloud SQL Proxy?

A4: The official project is hosted on : https://github.com/GoogleCloudPlatform/cloudsql-proxy. The changelog and release notes there will contain the definitive information on security fixes.

Q5: What should I do if I cannot immediately update the proxy in production?

A5: If an immediate update poses a business risk, implement stringent network-level controls as a temporary mitigation. Restrict access to the proxy's port(s) using to only allow connections from authorized application servers. This reduces the attack surface but is not a substitute for applying the security patch.