CVE-2025-48056 is a medium-severity vulnerability affecting versions of the Cilium Hubble CLI prior to 1.17.2. Hubble is a distributed networking and security observability platform designed for cloud-native workloads, providing Layer 7 protocol visibility and network flow monitoring. The vulnerability arises from improper neutralization of special control characters in the CLI output, classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component, commonly known as injection). Specifically, a network attacker who can intercept or influence Kafka traffic monitored by Hubble's Layer 7 Protocol Visibility feature can inject malicious control characters into the terminal output. This injection can manipulate the CLI display by concealing log entries, rewriting output, or rendering the terminal temporarily unusable. The attack does not affect confidentiality or availability directly but compromises the integrity and reliability of the monitoring output, potentially misleading operators or hiding malicious activity. Exploitation requires no privileges or user interaction but does require that the victim is actively monitoring Kafka traffic with Hubble at the time of the attack. The issue was addressed in Hubble CLI version 1.17.2 by properly sanitizing output to neutralize control characters. Users unable to upgrade are advised to redirect Hubble flows to log files and inspect them with text editors rather than relying on terminal output. No known exploits are currently reported in the wild.

For European organizations, especially those operating cloud-native environments with Kubernetes and using Cilium Hubble for network observability, this vulnerability poses a risk to the integrity of network monitoring data. Attackers could manipulate or hide network flow information, potentially allowing malicious activities to go undetected or mislead security analysts. This could delay incident response and forensic investigations, increasing the risk of prolonged compromise. While the vulnerability does not directly expose sensitive data or cause denial of service, the loss of trust in monitoring outputs can have significant operational impacts. Organizations relying on Kafka traffic monitoring in critical infrastructure sectors such as finance, telecommunications, or government cloud deployments are particularly at risk. Given the increasing adoption of cloud-native technologies across Europe, the vulnerability could affect a broad range of enterprises and service providers.

1. Upgrade Hubble CLI to version 1.17.2 or later immediately to apply the patch that neutralizes control characters in output. 2. For environments where immediate upgrade is not feasible, configure Hubble to redirect flow outputs to log files instead of terminal output, and analyze these logs using trusted text editors that do not interpret control characters. 3. Implement network segmentation and strict Kafka traffic controls to limit exposure to untrusted network actors who could attempt injection. 4. Monitor for anomalous terminal behavior or unexpected output manipulation during Kafka traffic monitoring sessions. 5. Incorporate integrity verification mechanisms for monitoring outputs, such as cryptographic logging or out-of-band verification, to detect tampering. 6. Educate security teams about this vulnerability to ensure awareness and prompt response if suspicious output is observed.