CVE-2025-27025

Executive Summary

CVE-2025-27025 is a critical vulnerability in Infinera G42 network equipment that allows authenticated remote attackers to perform directory traversal attacks via a web service endpoint, achieving arbitrary file read and write capabilities on the device file system with root privileges. The vulnerability carries a CVSS score of 8.8 (High) and affects the confidentiality, integrity, and availability of the device. There is currently no patch available from the vendor, and the vulnerability remains unpatched across all known versions of the affected software. Due to the severity of this flaw—particularly the arbitrary file write capability as root—any attacker who successfully compromises the Basic Authentication credentials can gain complete control of the affected network device.

Technical Analysis

The vulnerability resides in the web management interface of Infinera G42 devices, which expose a service on a TCP port with a configured endpoint. The endpoint is protected by Basic Authentication, requiring valid credentials to access the service. However, the architectural flaw lies in the combination of several dangerous configuration elements:

Authentication Weakness: The service relies on Basic Authentication, which transmits credentials in plaintext (Base64-encoded) over the network. If the service is not configured to use TLS/HTTPS, credentials are exposed to network sniffing. Additionally, Basic Authentication relies on a single-factor credential set that, once compromised, grants broad access to the service.

Unrestricted HTTP Methods: The configured endpoint accepts both GET and PUT methods. While GET methods are typically read-only operations, the implementation allows reading any file from the device file system. Similarly, the PUT method permits writing files to arbitrary locations on the file system. The critical issue is that the endpoint does not enforce any path validation, allowing directory traversal sequences (e.g., ../, absolute paths, or encoded traversal patterns) to escape the intended root directory.

Privilege Escalation via File Permissions: Files written through this vulnerable endpoint are created with root privileges. This is particularly dangerous because it means an attacker can write files to any location on the file system, including system configuration files, cron job definitions, SSH authorized keys, or any other location that requires elevated privileges.

Lack of Input Validation: The endpoint fails to validate or sanitize the file path provided in the request. Combined with file write capability, this allows an authenticated attacker to:

• Overwrite critical system files (e.g., /etc/passwd, startup scripts, service configurations)
• Plant malicious executables or scripts that run with root privileges
• Modify network configuration to redirect traffic, intercept data, or establish persistent backdoors

Read Capability: The same mechanism, using GET requests, allows the attacker to read any file on the system. This includes:

• Configuration files containing credentials (including other administrative passwords)
• Network routing tables and ACL configurations
• Cryptographic keys, certificates, and other sensitive material
• Customer data or monitoring information stored on the device

The vulnerability class is Improper Path Traversal combined with Arbitrary File Write/Read, and the attack vector is network-based, requiring low privilege (a valid Basic Authentication credential) and no user interaction. The success of the attack does not depend on any special conditions, making it trivially exploitable once credentials are obtained.

There is insufficient technical detail in the NVD description to identify specific API endpoint names, file paths, or application-level function names. The description does, however, explicitly confirm that directory traversal is possible using standard HTTP tools like Postman, and that both file read and write operations can be performed.

Exploitation Scenarios

Scenario 1: Complete Device Compromise via File Write

1. Reconnaissance/Target Identification: An attacker performs network scanning to identify Infinera G42 devices, which typically expose management interfaces on well-known TCP ports. Shodan queries can identify devices with identifiable banners or service fingerprints associated with Infinera G42.

2. Credential Acquisition: The attacker obtains valid credentials through one of several methods—network sniffing (if the service does not use TLS), credential stuffing, brute-force attacks on the Basic Authentication service, or by leveraging previously compromised credentials from other systems.

3. Triggering the Vulnerability: Using a tool like Postman or cURL, the attacker authenticates to the service and constructs a PUT request to the vulnerable endpoint with a directory traversal path. For example, a request containing ../../../../etc/crontab or an absolute path like /etc/crontab would escape the web root and target system files.

4. Payload Execution: The attacker writes a malicious script or executable to a location that will be executed with root privileges, such as:

   • A cron job that downloads and executes a reverse shell
   • An SSH authorized key file (/root/.ssh/authorized_keys) granting persistent access
   • A startup script that runs arbitrary commands on each boot

5. Post-Exploitation Impact: With root access, the attacker gains full control of the device. This allows for:

   • Network traffic interception and modification
   • Installing persistent backdoors
   • Exfiltrating sensitive data from the device and the network it manages
   • Disrupting network services (availability impact)

Scenario 2: Sensitive Information Disclosure

1. Reconnaissance: Same as above—identify Infinera G42 devices and obtain credentials.

2. Exploitation: Instead of writing files, the attacker uses GET requests. By sending a GET request to the endpoint with a traversal path, the attacker retrieves any file from the device file system.

3. Data Collection: The attacker systematically reads:

   • Configuration files containing credentials for other systems (e.g., SNMP community strings, RADIUS/TACACS+ shared secrets, neighboring device credentials)
   • Network topology information and routing configurations
   • Cryptographic keys and certificates that might allow decryption of traffic
   • Any customer data or telemetry information stored on the device

4. Lateral Movement: The exfiltrated credentials and configuration data enable the attacker to pivot into the broader network infrastructure, potentially compromising additional devices, servers, and services beyond the initial target.

No public exploit code is available; however, the attack chain is straightforward given the vulnerability description and the availability of the mechanism through standard HTTP tools. The attack requires only low-level privileges (valid API credentials), making it a realistic threat for any enterprise deploying Infinera G42 equipment.

Impact Assessment

CVSS Analysis: The vulnerability has a CVSS 3.1 base score of 8.8 with the vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. This indicates:

• Attack Vector: Network (AV:N) — The vulnerability is exploitable remotely over the network, increasing the attack surface to all reachable network interfaces.
• Attack Complexity: Low (AC:L) — No special conditions, race conditions, or complex exploitation techniques are required; a straightforward HTTP request is sufficient.
• Privileges Required: Low (PR:L) — Only a valid Basic Authentication credential is needed, which is often shared or poorly protected in network infrastructure environments.
• User Interaction: None (UI:N) — No victim interaction is required.
• Scope: Unchanged (S:U) — The vulnerability affects only the target device's security context.
• Confidentiality Impact: High (C:H) — Arbitrary file read allows complete information disclosure from the device file system.
• Integrity Impact: High (I:H) — Arbitrary file write allows modification of system files, configurations, and planted malicious content.
• Availability Impact: High (A:H) — File overwrite can render the device inoperable or cause a denial-of-service condition.

Business Impact:

1. Operational Disruption: Network devices running Infinera G42 are typically part of telecom or ISP infrastructure. Compromise could cause service outages, degraded performance, or complete failure of network segments.

2. Data Breach: The file read capability exposes configuration data, credentials, and potentially customer-related information on the device, which could constitute a reportable data breach.

3. Supply Chain Risk: The device is presumed to be Infinera-manufactured. Compromising these devices could allow attackers to intercept traffic at the carrier level, affecting multiple downstream customers and organizations.

4. Regulatory Consequences: Depending on the deployment environment (e.g., critical infrastructure, telecom regulatory frameworks), a breach could trigger mandatory incident reporting and regulatory scrutiny.

5. Blast Radius: The affected systems are network infrastructure devices, meaning the blast radius extends beyond the single device to the entire network segment it manages. An attacker controlling a G42 device can redirect traffic, capture communications, inject malicious content, and enable further lateral movement.

6. EPSS Score: The EPSS score of 0.00635 (47.1% percentile) indicates that while exploitation has not been widely observed in the wild yet, the vulnerability is within the top half of scored vulnerabilities and interest is likely to increase once public exploit techniques are fully documented.

Detection Guidance

Sigma Rule

Detect directory traversal attempts against Infinera G42 management endpoints. The rule monitors HTTP proxy/access logs for traversal patterns in PUT/GET requests to the target device.

title: Suspicious Directory Traversal on Infinera G42
id: 3d6c1ab5-8a2e-4c9f-b3f4-9a1190e21e44
status: experimental
description: Detects path traversal attempts targeting Infinera G42 device management interface
author: Valtersit Threat Intelligence
date: 2025/03/15
logsource:
  category: webserver
  product: apache
  definition: 'HTTP access logs from proxies or device service logs covering Infinera G42 management interface'
detection:
  selection_traversal:
    c-uri|contains:
      - '..%2f'
      - '..%5c'
      - '/../'
      - '/..%2f'
  selection_paths:
    c-uri|contains:
      - '/etc/'
      - '/var/'
      - '/bin/'
      - '/usr/'
      - '/tmp/'
      - '/root/'
  selection_methods:
    cs-method:
      - 'PUT'
      - 'GET'
      - 'POST'
  condition: selection_traversal and selection_paths and selection_methods
  timeframe: 5m
level: critical
falsepositives:
  - Legitimate administrative operations by network engineers using maintenance tools
  - Monitoring software that reads device metrics via web service
tags:
  - attack.t1190
  - attack.initial-access
  - cve.2025-27025
  - cwe.22

YARA Rule

Identifies artifacts of CVE-2025-27025 exploitation attempts in device logs or captured network traffic.

rule Infinera_G42_Traversal_Exploitation {
    meta:
        author = "Valtersit Threat Intelligence"
        description = "Detects patterns associated with CVE-2025-27025 exploitation attempts"
        cve = "CVE-2025-27025"
        creation_date = "2025-03-15"
        confidence = "50"
        impact = "high"
        category = "exploitation"

    strings:
        // Traversal patterns in URI
        $traversal1 = "/../" ascii
        $traversal2 = "/..%2f" ascii nocase
        $traversal3 = "..\\" ascii nocase
        $traversal4 = "..%5c" ascii nocase
        $traversal5 = "%2e%2e%2f" ascii nocase

        // Sensitive system paths targeted
        $path1 = "/etc/" ascii nocase
        $path2 = "/var/" ascii nocase
        $path3 = "/root/" ascii nocase
        $path4 = "/tmp/" ascii nocase
        $path5 = "/dev/" ascii nocase

        // HTTP methods used
        $method_put = "PUT" ascii
        $method_get = "GET" ascii

        // Authentication header patterns
        $basic_auth = "Authorization: Basic" ascii

    condition:
        any of ($traversal*) and any of ($path*) and (any of ($method_*))
}

Suricata IDS Rule

Suricata signature to detect directory traversal attempts against Infinera G42 management interfaces on the network.

alert http any any -> any any (
    msg:"ET EXPLOIT Infinera G42 Directory Traversal Attempt (CVE-2025-27025)";
    flow:established,to_server;
    http.method; content:"PUT|20|/"; http.uri; content:".."; http.uri; content:"/"; 
    distance:0; within:10;
    content:"/etc/"; http.uri;
    sid:2025031501;
    rev:1;
    metadata:created_at 2025_03_15, updated_at 2025_03_15, cve CVE-2025-27025, cvss 8.8, mitre_attack T1190;
    reference:url,nvd.nist.gov/vuln/detail/CVE-2025-27025;
    classtype:attempted-admin;
    priority:1;
)

This signature is intentionally broad to catch any traversal pattern regardless of the path; adjust the targets based on known device file paths for the specific deployment.

Elastic Detection

EQL rule for detecting exploitation attempts against Infinera G42 devices in Elastic SIEM.

any where event.category == "web" and 
  /* Monitor traffic to Infinera G42 portals */
  (
    /* Traversal patterns in URI */
    url.full : "*/../*" or
    url.full : "*..%2f*" or
    url.full : "*..%5c*" or
    url.full : "*%2e%2e*" or
    
    /* Requests targeting sensitive paths */
    url.path : "*/etc/*" or
    url.path : "*/var/*" or
    url.path : "*/root/*" or
    url.path : "*/bin/*" or
    url.path : "*/usr/*"
  ) and
  (
    http.request.method : "PUT" or
    http.request.method : "GET"
  ) and
  /* Ignore normal legitimate traffic patterns */
  not (url.path : "/etc/passwd" and http.request.method : "GET" and source.ip : "10.0.0.0/8")

Splunk SPL Query

Search for potential exploitation attempts against the Infinera G42 device management interface.

index=network sourcetype=stream:http dest_port=* 
  (curl_status=200 OR curl_status=401 OR curl_status=404) 
  (http_method="PUT" OR http_method="POST" OR http_method="GET")
  (uri="*/../*" OR uri="*..%2f*" OR uri="*..%5c*" OR uri="*%2e%2e*")
  OR
  (uri="*/etc/*" OR uri="*/var/*" OR uri="*/root/*" OR uri="*/bin/*")
  OR
  (uri="*%2fetc%2f*" OR uri="*%2ftmp%2f*")
| table _time, src_ip, dest_ip, dest_port, http_method, uri, http_user_agent, response_code
| sort - _time
| eval threat = "CVE-2025-27025" 
| stats count by src_ip, dest_ip, http_method, uri

Wazuh OSSEC Rule

Wazuh rule to detect CVE-2025-27025 exploitation attempts by monitoring web logs for traversal patterns.

<group name="infinera,cve-2025-27025,">
  <rule id="100270" level="12">
    <decoded_as>web-access</decoded_as>
    <match>PUT|GET|POST</match>
    <regex>\.\.(\/|%2f|\\|%5c)|%2e%2e|etc\/|var\/|root\/|bin\/|usr\/|tmp\/|dev\/</regex>
    <description>Directory traversal attempt detected - Infinera G42 (CVE-2025-27025)</description>
    <group>web_application_attack</group>
    <mitre>
      <id>T1190</id>
    </mitre>
    <alert>
      <severity>high</severity>
      <type>exploit</type>
      <cve>CVE-2025-27025</cve>
    </alert>
    <options>no_full_log</options>
  </rule>
</group>

Mitigation & Patch Guidance

PATCH STATUS: Unpatched (0/4 confidence) — No patch is available from Infinera or any other tracked vendor source. There is no evidence of vendor acknowledgment, fix release, or workaround documentation from the vendor. Organizations must treat the device as permanently compromised until vendor remediation is available.

Immediate Mitigations (to deploy while awaiting patch):

1. Network Segmentation: Isolate the Infinera G42 management interface from the general corporate network. Place management interfaces on a dedicated, restricted VLAN or management network segment. Use firewalls to restrict access to only authorized administrative workstations.

2. Restrict Access by Source IP: Implement strict IP allowlists at the firewall level. Only allow management traffic from specific, known administrative IP addresses; deny all other source addresses.

3. Disable or Restrict the Vulnerable Service: If the endpoint is not essential for business operations, disable the web management interface entirely. If it must remain operational, consider using an HTTP reverse proxy that can filter and block requests containing traversal patterns.

4. Enforce Strong Authentication: Change the credentials used for Basic Authentication. Use long, complex, unique passwords. Implement two-factor authentication if the device or surrounding infrastructure supports it. Regularly rotate credentials.

5. Enable TLS/Encryption: Ensure all traffic to the management interface is protected with TLS/HTTPS to prevent credential sniffing over the network.

6. Monitor Actively: Deploy the detection rules provided in this report in your SIEM/IDS infrastructure. Create a dedicated alerting channel for any matches associated with CVE-2025-27025.

7. Immediate Credential Reset: If there is any suspicion of a prior breach, reset all credentials that might be used to access the device, including any shared/administrative passwords.

Patch/Upgrade Steps:

1. Contact Infinera support immediately. Open a support ticket referencing CVE-2025-27025 and request a timeline for a fix or a security advisory.

2. Check the Infinera security advisory portal periodically for announcements related to this CVE. Subscribe to vendor security mailing lists if available.

3. Upon release of a patch, test it in a staging environment that mirrors your production deployment, then schedule a maintenance window for deployment. Document the patched version for compliance.

Long-Term Hardening:

1. Minimize Attack Surface: Disable all unused services and endpoints on the device. The Basic Authentication mechanism described suggests the service is web-based; evaluate whether the web interface is necessary or if CLI-only access would suffice for configuration.

2. Inventory and Lifecycle Management: Maintain an accurate inventory of all Infinera G42 devices in your environment, including model, firmware version, and patch status. Implement a vulnerability management process to track and remediate known vulnerabilities.

3. Network Architecture Review: Ensure management interfaces are not directly exposed to the internet. Place them behind VPN or dedicated management access solutions that enforce MFA and granular access control.

4. Credential Hygiene: Move to certificate-based authentication or other modern authentication mechanisms if the device supports them. Avoid shared accounts. Implement a central identity management solution that ensures unique per-user credentials.

5. Continuous Monitoring: Deploy network traffic monitoring and anomaly detection at device and network levels. Look for unusual HTTP methods, traversal patterns, and unexpected file access.

6. Incident Response Preparedness: Create an incident response playbook specific to network infrastructure compromise. Include steps for isolating affected devices, forensic data collection, and communication protocols with the vendor.

7. Regular Security Assessments: Include Infinera G42 devices in regular penetration testing and vulnerability scanning activities to identify new risks and ensure mitigations remain effective.

References

1. NVD Entry for CVE-2025-27025: https://nvd.nist.gov/vuln/detail/CVE-2025-27025 — Official NVD record with CVSS scoring, description, and current vulnerability status.

2. MITRE ATT&CK — T1190 Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/ — The primary MITRE tactic associated with this vulnerability.

3. CWE-22 Improper Limitation of a Pathname to a Restricted Directory (Path Traversal): https://cwe.mitre.org/data/definitions/22.html — The CWE classification that best fits the described vulnerability mechanism.

4. Infinera Product Security Page: https://www.infinera.com/support/security/ — Check for vendor security advisories, patch announcements, and contact for responsible disclosure.

5. CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog — Currently CVE-2025-27025 is NOT listed in CISA KEV, but this resource should be monitored for updates.

Threat Actor Activity: As of the writing of this report, no specific threat actor campaigns have been publicly attributed to this CVE. The vulnerability is not known to be exploited in the wild, and no ransomware groups or APT actors have been documented as targeting this specific flaw. The EPSS score of 0.00635 indicates a low but non-trivial probability of exploitation in the wild; interest is likely to increase as the vulnerability receives more public attention.

Exploit-in-the-Wild Evidence: The NVD description confirms that exploitation is possible using the Postman tool, and there is no patch available. While no malicious in-the-wild exploitation has been confirmed, the combination of an unpatched critical vulnerability with public PoC information (the Postman-based technique discussed in the description) creates a high-risk environment. Organizations should treat this as a priority for immediate mitigation despite the lack of documented in-the-wild attacks.