CVE-2022-1702: SonicWall SMA Open Redirect Vulnerability

CVE-2022-1702 Overview

CVE-2022-1702 is an Open Redirection vulnerability affecting SonicWall SMA1000 series appliances running firmware versions 12.4.0, 12.4.1-02965 and earlier. The vulnerability allows attackers to craft malicious links that redirect users from trusted SonicWall domains to attacker-controlled external sites, facilitating phishing attacks and credential theft.

Critical Impact

Attackers can leverage trusted SonicWall SMA1000 appliances to redirect users to malicious websites, potentially enabling credential harvesting, malware delivery, and social engineering attacks against enterprise users.

Affected Products

• SonicWall SMA 6200 Firmware 12.4.0, 12.4.1
• SonicWall SMA 6210 Firmware 12.4.0, 12.4.1
• SonicWall SMA 7200 Firmware 12.4.0, 12.4.1
• SonicWall SMA 7210 Firmware 12.4.0, 12.4.1
• SonicWall SMA 8000v Firmware 12.4.0, 12.4.1

Discovery Timeline

• 2022-05-13 - CVE CVE-2022-1702 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-1702

Vulnerability Analysis

This vulnerability is classified as CWE-601 (URL Redirection to Untrusted Site, also known as Open Redirect). The SonicWall SMA1000 series firmware contains a vulnerable endpoint that accepts user-controlled input specifying a redirect destination URL. The application fails to properly validate or sanitize this URL parameter before using it to construct an HTTP redirect response.

When a user clicks on a crafted link pointing to the vulnerable SonicWall appliance, the application processes the malicious URL parameter and issues a redirect to the attacker-specified external site. Because the initial link appears to originate from a legitimate and trusted SonicWall appliance, users are more likely to trust the redirect destination.

This vulnerability requires user interaction—a victim must click on a malicious link. However, the network-accessible nature of SMA1000 appliances and the changed scope of the vulnerability (affecting resources beyond the vulnerable component) increase the potential impact for confidentiality and integrity compromise.

Root Cause

The root cause of CVE-2022-1702 is insufficient input validation on URL redirect parameters within the SonicWall SMA1000 series firmware. The application accepts arbitrary external URLs without validating them against a whitelist of trusted destinations or enforcing same-origin restrictions. This allows attackers to inject any URL as the redirect target.

Proper secure coding practices would require the application to either restrict redirects to relative URLs within the same domain, validate destination URLs against an approved whitelist, or implement warning pages when redirecting to external domains.

Attack Vector

The attack is network-based and exploits the trust relationship users have with their organization's SonicWall appliances. An attacker can craft a malicious URL that includes the legitimate SonicWall SMA1000 address followed by a vulnerable endpoint and an attacker-controlled redirect parameter.

The attack flow typically involves:

1. Attacker identifies a vulnerable SonicWall SMA1000 appliance exposed to the network
2. Attacker crafts a malicious URL containing the legitimate appliance address with a redirect parameter pointing to a phishing site
3. Attacker distributes the malicious link via phishing emails, compromised websites, or social engineering
4. Victim clicks the link, trusting the apparent SonicWall domain
5. The SonicWall appliance redirects the victim to the attacker-controlled site
6. Victim may enter credentials or download malware from the malicious destination

Detection Methods for CVE-2022-1702

Indicators of Compromise

• Unusual outbound redirects from SonicWall SMA1000 appliances to external domains
• Web server logs showing requests with suspicious URL parameters containing external URLs
• Reports from users about unexpected redirects after clicking links to SonicWall resources
• Phishing attempts leveraging your organization's SonicWall appliance URLs

Detection Strategies

• Monitor web application logs for requests containing URL parameters with external domain references
• Implement web application firewall (WAF) rules to detect and block redirect manipulation attempts
• Deploy network traffic analysis to identify redirect chains originating from SonicWall appliances
• Review DNS query logs for connections to suspicious domains following SonicWall appliance access

Monitoring Recommendations

• Enable verbose logging on SonicWall SMA1000 appliances to capture full request URLs
• Configure SIEM alerts for anomalous redirect patterns from remote access infrastructure
• Implement URL reputation checking for destinations in redirect parameters
• Establish baseline patterns for legitimate redirect behavior and alert on deviations

How to Mitigate CVE-2022-1702

Immediate Actions Required

• Update all SonicWall SMA1000 series appliances to patched firmware versions beyond 12.4.1-02965
• Review access logs for evidence of exploitation attempts
• Alert users about potential phishing attempts using SonicWall URLs
• Implement additional web filtering to block known malicious redirect destinations

Patch Information

SonicWall has released security updates to address this vulnerability. Administrators should consult the SonicWall Vulnerability Advisory SNWLID-2022-0009 for specific patched firmware versions and upgrade instructions.

Organizations running firmware versions 12.4.0 or 12.4.1-02965 and earlier on SMA 6200, SMA 6210, SMA 7200, SMA 7210, or SMA 8000v appliances should prioritize upgrading to the latest available firmware release.

Workarounds

• Deploy a reverse proxy or WAF in front of SonicWall appliances to filter malicious redirect parameters
• Implement network segmentation to limit exposure of SonicWall management interfaces
• Configure email gateway rules to flag or block links containing suspicious redirect patterns to SonicWall URLs
• Educate users to verify final destination URLs before entering credentials, even when links appear to originate from trusted infrastructure

# Configuration example - WAF rule to block open redirect attempts
# Example ModSecurity rule to detect external URL in redirect parameter
SecRule ARGS "@rx https?://[^/]*\.(ru|cn|xyz|tk)" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    msg:'Potential Open Redirect Attack Detected',\
    logdata:'Matched Data: %{MATCHED_VAR} found within %{MATCHED_VAR_NAME}'"