CVE-2025-54083

Executive Summary

CVE-2025-54083 describes an insecure storage of sensitive information vulnerability in Calix GigaCenter ONT devices using Quantenna SoC modules. This flaw allows an attacker with admin-level access to the web interface to retrieve stored credentials or secrets, potentially leading to full device compromise. The affected models include 844E, 844G, 844GE, and 854GE. No public exploit or patch details are available at this time.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level issue in Calix ONT hardware.

CVSS Breakdown & Threat Level

CVSS Score: 0.0 (No official vector assigned)
Given the nature of the vulnerability (insecure storage of sensitive information), a reasonable CVSSv3.1 vector would be:
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
This yields a score of approximately 4.9 (Medium). The attack vector is network-based, requires high privileges (admin), and impacts confidentiality only.

Deep Dive & Mechanics

The vulnerability resides in the web interface of Calix GigaCenter ONT devices. The Quantenna SoC modules store sensitive information (e.g., credentials, tokens) in an insecure manner, such as in plaintext or weakly encrypted files accessible via the admin web interface. An authenticated admin can retrieve this data, potentially leading to lateral movement or privilege escalation within the network.

The exact mechanism is not publicly documented, but typical insecure storage issues involve:

• Storing passwords in world-readable configuration files
• Using reversible encryption or hardcoded keys
• Exposing secrets via API endpoints without proper access controls

Vulnerable vs. Patched Code

No patch or code comparison is available. The vulnerability is unpatched as of the latest advisory.

Exploitation & Lab Setup

Red Team

No public exploit code exists. To simulate the attack in a lab:

1. Obtain a Calix GigaCenter ONT (844E, 844G, 844GE, or 854GE).
2. Gain admin access to the web interface (e.g., via default credentials or brute force).
3. Navigate to configuration or system settings pages.
4. Extract stored credentials or tokens from exposed fields or downloadable config files.

Example manual extraction:

curl -u admin:password http://<device-ip>/config_backup.bin -o config.bin
strings config.bin | grep -i password

Blue Team

To detect exploitation:

• Monitor for unusual admin logins to the web interface.
• Alert on bulk downloads of configuration files.
• Use network monitoring to detect exfiltration of sensitive data.

Indicators of Compromise (IOCs)

• Unusual admin login attempts from unexpected IPs
• Large outbound data transfers from the ONT device
• Configuration file downloads (e.g., config_backup.bin)
• Presence of plaintext credentials in logs or network traffic

Detection Engineering

YARA Rule

rule CVE_2025_54083_Calix_ONT_Insecure_Storage {
    meta:
        description = "Detects insecure storage of sensitive info in Calix ONT config files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-54083"
    strings:
        $s1 = "password" ascii wide nocase
        $s2 = "secret" ascii wide nocase
        $s3 = "admin" ascii wide nocase
        $s4 = "config_backup" ascii wide nocase
    condition:
        any of ($s1, $s2, $s3) and $s4
}

Sigma Rule

title: Calix ONT Insecure Storage Detection
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects potential exploitation of CVE-2025-54083 via config file download
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains: "config_backup"
    condition: selection
falsepositives:
    - Legitimate admin backup operations
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-54083 Calix ONT Config File Download";
    flow:to_server,established;
    content:"config_backup"; http_uri;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

• Immediate: Restrict admin access to the web interface via IP whitelisting or VPN.
• Short-term: Change default credentials and monitor for unauthorized access.
• Long-term: Apply firmware patches from Calix when available. Consider replacing affected devices if no patch is released.
• Compensating controls: Use network segmentation to isolate ONT devices from critical assets.

Valters IT
DevSecOps & Cyber Threat Intelligence