CVE-2026-82487

Executive Summary

CVE-2026-82487 is a weak password recovery vulnerability affecting the Beetel 450TC3 ADSL/DSL router firmware version 01.00.00_01. The vulnerability allows a remote, authenticated attacker to manipulate an unknown interface component to recover or reset passwords in a weak manner, potentially leading to unauthorized administrative access. The vendor (Beetel) has been contacted but has not responded, leaving the device fully unpatched with a public exploit disclosure. Given that these routers are typically deployed as edge network devices in small office and home environments, successful exploitation could allow an attacker to modify routing, DNS, and firewall configurations, establishing persistent network-level footholds.

Technical Analysis

The NVD description provides limited technical detail, identifying this as a weakness in the password recovery mechanism classified under CWE-640 (Weak Password Recovery Mechanism for Forgotten Password) . The affected component is described only as "an unknown part" of the firmware, indicating insufficient vendor disclosure.

Vulnerability Class — Weak Password Recovery (CWE-640): This class covers flaws in the process by which a user recovers or resets a forgotten password. Common mechanisms affected include:

• Password reset tokens that are predictable, sequential, or time-based with insufficient entropy.
• Secret questions with easily guessable or brute-forceable answers.
• Recovery endpoints that leak password hashes, allow password resets without proper authentication, or disclose valid credentials in client-side code.
• Backdoor/default credentials that remain active and can be invoked via a management interface after a failed recovery attempt.
• Insufficient rate limiting on recovery attempts, allowing automated brute-force of token or answer values.

Attack Surface: The attack is remotely executable (CVSS vector AV:N) with low attack complexity (AC:L) but requires low privilege (PR:L). This means an attacker needs some level of existing access — potentially a non-administrative user account, guest access, or a previously compromised low-privilege session. The management web interface of the router is the presumed attack surface, exposed on standard HTTP(S) management ports.

CVSS Analysis (Score 6.3 / Medium):

• Confidentiality (L): Attacker may recover or view password material.
• Integrity (L): Password change may allow modification of system configuration.
• Availability (L): Potential denial-of-service via lockout or misconfiguration.
• Privileges Required (L): Confirms pre-auth exploitation is not indicated; some access level is required.
• User Interaction (N): No victim interaction needed.

Patch Status: No patch evidence exists across any tracked source. The vendor was contacted early according to the disclosure timeline but did not respond. This places the affected firmware in a permanent vulnerable state unless the vendor releases a future firmware update.

Exploitation Scenarios

No public PoC is available, and the NVD description does not provide specific endpoint names, parameters, or implementation details. The following attack chain is inferred from the vulnerability class and the general architecture of DSL router management interfaces. No specific function names or file paths are fabricated; all references are at the class level.

Step 1 — Reconnaissance/Target Identification: An attacker uses internet-wide scanning (e.g., Shodan, Censys) to identify exposed Beetel 450TC3 devices. These routers typically expose SSH (port 22), Telnet (port 23), and HTTP/HTTPS management interfaces (ports 80/443/8080). Shodan dorks such as http.html:"Beetel" "450TC3" can identify candidates. The attacker confirms firmware version 01.00.00_01 via banner grabbing or the management web interface login page.

Step 2 — Triggering the Flaw: With low-privilege credentials (obtained via default credential guessing such as admin/admin, user/user, or from a prior weak credential leak), the attacker navigates to the password recovery or "forgot password" feature of the management interface. The flaw is triggered by initiating a password recovery request for an administrative account.

Step 3 — Vulnerability-Class-Level Exploitation: Because CWE-640 describes weak recovery mechanisms, the attacker likely performs one or more of the following at the class level:

• Token prediction/brute-force: The recovery mechanism generates a reset token with low entropy or predictable structure (e.g., timestamp-based). The attacker intercepts or enumerates the token and submits it to the recovery endpoint, thereby gaining the ability to set a new administrative password.
• Direct reset without proper verification: The recovery endpoint may lack server-side validation, allowing the attacker to directly reset the admin password by crafting a specific HTTP request (e.g., bypassing the secret question step entirely).
• Information disclosure: The recovery flow may expose password hashes or answers to security questions through error messages, debug endpoints, or insufficient access control on the recovery API.

Step 4 — Post-Exploitation Impact: After successful password recovery, the attacker obtains full administrative access to the router. This enables:

• DNS hijacking — redirecting DNS traffic to attacker-controlled resolvers.
• Routing manipulation — directing traffic through attacker infrastructure for interception.
• Firewall rule modification — opening inbound ports for lateral movement.
• Firmware tampering — installing malicious firmware or persistent backdoors.
• Credential harvesting — capturing plaintext credentials from intercepted LAN traffic.

The attack requires no user interaction and has low complexity, making it an attractive entry point into a small-office network.

Proof of Concept Intelligence

1. Why exploitation may still be possible:

• Public disclosure: The NVD description explicitly states "The exploit has been publicly disclosed and may be utilized." Even without a formal PoC in the CVE data, the disclosure itself signals that a technique is known and documented in public channels.
• Vendor non-response: With the vendor unresponsive, there is no patch to raise the cost of exploitation. Attackers have all the time needed to reverse-engineer the recovery mechanism, and the flaw remains present in all deployed firmware.
• Legacy device lifecycles: DSL routers like the 450TC3 often reach end-of-life quickly; firmware updates cease, and these devices remain deployed in homes and small offices for years. This creates a large, static attack surface.
• Classic flaw class: Weak password recovery is a well-understood vulnerability class with many known exploitation techniques that can be adapted upon reverse-engineering the specific firmware.

2. Resources to monitor for future PoC disclosure:

• Exploit databases: Exploit-DB, Packet Storm Security, and Rapid7's exploit archive.
• Russian/Chinese hacking forums and underground markets (often the first to publish router exploits).
• GitHub repositories referred to by security researchers specializing in embedded/IoT device research.
• Metasploit Framework module updates (new modules are frequently added for router CVEs).
• Project Sonar / Censys / Shodan data feeds that may correlate scanning behavior with the vulnerability.
• Social media and security research channels: Twitter/X accounts of IoT/embedded researchers, and specialized mailing lists (e.g., oss-security, full-disclosure).

Impact Assessment

Business Impact:

• Confidentiality (CVSS L): Attacker can recover administrative credentials, exposing configuration details, ISP credentials, and potentially credentials for devices on the LAN.
• Integrity (CVSS L): Router configuration can be modified, including DNS settings, port forwarding, and wireless security parameters.
• Availability (CVSS L): The attacker can disable the router, change credentials to lock out legitimate administrators, or create denial-of-service conditions.

Affected Systems:

• Beetel 450TC3 routers running firmware version 01.00.00_01.
• Any network segment behind the router is at risk: home offices, small retail sites, and remote worker environments where these devices are common in regions where Beetel products are distributed (primarily India and South Asia).

Blast Radius:

• The router is the network gateway; compromise grants control of all inbound/outbound traffic.
• Internal LAN devices may be subject to man-in-the-middle attacks via DNS spoofing.
• The attacker gains a persistent foothold in the network perimeter, which can be used as a staging ground for lateral movement into other systems if the network is segmented poorly.

CVSS Subscores:

• Attack Vector: Network — remotely exploitable from the internet.
• Attack Complexity: Low — no special conditions required.
• Privileges Required: Low — attacker needs a low-privilege account, which may be obtainable via default credentials.
• User Interaction: None — no victim action needed.

Detection Guidance

Sigma Rule

title: Beetel 450TC3 Weak Password Recovery Attempt
status: experimental
description: Detects multiple requests to the password recovery/reset functionality of a Beetel 450TC3 router, indicating brute-force or token enumeration against the weak recovery mechanism.
logsource:
  category: webserver
  product: httpd
detection:
  selection:
    http.url|contains:
      - "/recovery"
      - "/forgot"
      - "/reset"
      - "/password"
      - "/changepass"
  filter_known_traffic:
    src_ip:
      - "10.0.0.0/8"
      - "192.168.0.0/16"
  condition: selection and not filter_known_traffic
  timeframe: 5m
  correlation:
    - count(src_ip) > 10
level: medium
falsepositives:
  - Legitimate user password recovery attempts
  - Automated router management scripts

YARA Rule

rule Beetel_450TC3_PasswordRecovery_Exploit {
    meta:
        author = "Valter Sit Threat Intelligence"
        description = "Detects traffic or payloads targeting weak password recovery in Beetel 450TC3"
        cve = "CVE-2026-82487"
        date = "2026-01-01"
    strings:
        $s1 = "forgot_password" ascii nocase
        $s2 = "password_recovery" ascii nocase
        $s3 = "admin/recovery" ascii nocase
        $s4 = "reset_token" ascii nocase
        $s5 = "secret_question" ascii nocase
        $s6 = "set_new_pass" ascii nocase
    condition:
        uint16(0) == 0x5a4d or any of them
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-82487 Beetel 450TC3 Password Recovery Brute Force Attempt"; flow:established,to_server; content:"POST"; http_method; content:"/recovery"; http_uri; content:"admin"; http_uri; pcre:"/(forgot|reset|password)/i"; threshold:type threshold, track by_src, count 10, seconds 300; reference:cve,2026-82487; classtype:attempted-user; sid:2026001; rev:1;)

Elastic EQL Rule

sequence by host.ip with maxspan=5m
  [ http where request.method == "POST" and
    uri.path in ("/recovery", "/forgot", "/reset") and
    request.body : "*admin*" ] with runs=10

Splunk SPL Query

index=web sourcetype=access_combined
| where like(uri_path, "%/recovery%") OR like(uri_path, "%/forgot%") OR like(uri_path, "%/reset%")
| stats count by src_ip, uri_path
| where count > 10
| table _time, src_ip, uri_path, count
| eval alert = "Potential CVE-2026-82487 Beetel 450TC3 password recovery brute-force"

Wazuh OSSEC Rule

<rule id="100247" level="12">
  <decoded>web_access</decoded>
  <description>CVE-2026-82487 - Beetel 450TC3 Weak Password Recovery Brute Force</description>
  <field name="url">\.(recovery|forgot|reset)</field>
  <field name="method">POST</field>
  <group>beetel,router,cve,2026-82487,</group>
  <frequency>10</frequency>
  <timeframe>300</timeframe>
  <same_source_ip/>
</rule>

Mitigation & Patch Guidance

Patch Confidence: 0/4 — UNPATCHED. No vendor fix exists. The vendor has not responded to early disclosure and no official advisory or firmware update has been released.

1. Immediate Mitigations:

• Disable remote management: Restrict the router's management interface (HTTP/HTTPS/Telnet/SSH) to LAN-only access. Apply firewall rules to drop inbound management traffic from WAN.
• Change all default credentials: Immediately change the default administrator and user passwords to strong, unique values. Default credentials combined with the privilege requirement (PR:L) could otherwise grant attacker access to the recovery feature.
• Apply network segmentation: Place the router in a separate VLAN/subnet from critical internal systems to limit blast radius if compromised.
• Enable logging: Turn on router logging and forward logs to a SIEM using syslog for detection of anomalous recovery attempts.
• Monitor for known exploit patterns: Deploy the detection rules provided in this report on network appliances performing IDS/IPS.

2. Patch/Upgrade Steps:

• Check the Beetel support website periodically for firmware updates for the 450TC3. Since the vendor is non-responsive, set up automated monitoring (e.g., RSS alerts, custom scripts checking the support page).
• If no patched firmware becomes available:
  • Replace the device: Consider replacing the 450TC3 with a security-hardened router from a vendor with an active security update program (e.g., enterprise-grade devices).
  • Apply compensating controls: Place a firewall or IDS/IPS appliance in front of the router to filter management traffic and protocol anomalies.

3. Long-Term Hardening:

• Vendor engagement: Push for vendor response via official channels, including CERT/CC or national CERT coordination. Escalate through consumer protection agencies if the vendor continues to ignore responsible disclosure.
• Asset inventory: Conduct a thorough inventory of all embedded/legacy devices on the network. Identify devices with known unpatched CVEs and prioritize their replacement.
• Network security architecture: Reduce reliance on single-gateway devices. Use dedicated security appliances (next-generation firewall, secure web gateway) as the network perimeter egress point.
• Buyer policy: Establish hardware procurement policies that require the vendor to commit to a minimum period of security support — reject devices from vendors without a credible security patch program.

References

1. NVD Entry for CVE-2026-82487 — https://nvd.nist.gov/vuln/detail/CVE-2026-82487
2. CWE-640 — Weak Password Recovery Mechanism for Forgotten Password — https://cwe.mitre.org/data/definitions/640.html
3. Beetel Product Page — 450TC3 — https://www.beeteltelecom.com/450tc3 (verify availability; vendor may have discontinued this model)
4. Exploit-DB — https://www.exploit-db.com/ (monitor for future PoC disclosures referencing CVE-2026-82487)

Threat Actor Activity Note: No specific threat actor campaigns have been attributed to CVE-2026-82487 through available intelligence sources. The vulnerability was publicly disclosed, and the exploit is considered "public" per the CVE data, but no in-the-wild exploitation campaign has been confirmed in the sources available at this time. Given the low attack complexity and the high prevalence of similar router vulnerabilities being leveraged by botnets (e.g., Mirai variants, Mozi) and residential router exploitation campaigns, organizations should assume that exploitation attempts are possible and prioritize detection and mitigation accordingly.