Roundcube Webmail SQL Injection Vulnerability Security Advisory (CVE-2021-44026)
Executive & SecOps Summary
SECOPS ASSESSMENTRoundcube versions before 1.3.17 and 1.4.x versions before 1.4.12
Unauthenticated attackers can manipulate search parameters to extract sensitive database information or potentially achieve remote code execution (RCE)
Immediately upgrade Roundcube to the latest stable releases (1.3.17, 1.4.12, or higher)
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Official Patch & Version Upgrade Commands
Upgrade your Roundcube installation to the latest secure version using the package manager or by applying the official source patch.
# For Debian/Ubuntu systems
sudo apt-get update
sudo apt-get --only-upgrade install roundcube roundcube-core roundcube-plugins
# For manual source installations, download and run the upgrade script
wget https://github.com/roundcube/roundcubemail/releases/download/1.4.12/roundcubemail-1.4.12-complete.tar.gz
tar -zxvf roundcubemail-1.4.12-complete.tar.gz
cd roundcubemail-1.4.12
# Execute the installer to update the existing directory
sudo ./bin/installto.sh /var/www/roundcube2. Temporary Workaround & Hardening Configuration
If immediate patching is not feasible, deploy Web Application Firewall (WAF) rules or configure your web server to block suspicious search queries.
# Nginx configuration snippet to block common SQL injection patterns
if ($query_string ~* "(union|select|insert|delete|update|drop|char|declare|cast|convert|or|and)") {
return 403;
}
location / {
# Restrict access to trusted administrative IP ranges if applicable
allow 192.168.1.0/24;
deny all;
}3. Log Audit & IoC Verification Commands
Inspect web server access logs and database query logs for indicators of compromise (IoCs) targeting the search parameters.
# Scan web server access logs for SQL injection attempts in search parameters
grep -Ei 'search.*(select|union|concat|char|information_schema)' /var/log/nginx/access.log /var/log/apache2/access.log
# Verify the currently installed Roundcube version
grep "RCMAIL_VERSION" /var/www/roundcube/program/include/iniset.phpBlock Exploits Instantly with Managed Virtual Patching Rules
Can't patch production immediately? Deploy managed WAF rules at the edge to intercept RCE, SQLi, and deserialization payloads before they hit your origin server.
Technical Root Cause & Exploitation Mechanics
1. Vulnerability Overview & Root Cause
This vulnerability (CVE-2021-44026) is a critical SQL injection flaw in the Roundcube Webmail platform. The root cause lies in the insufficient sanitization and escaping of user-supplied input within the search and search_params parameters during email search operations. This allows attackers to inject arbitrary SQL commands directly into the database query execution flow.
2. Exploitation Mechanics & Attack Scenario
An attacker targets the email search API endpoints of the Roundcube web interface. By crafting malicious HTTP requests containing SQL syntax (such as single quotes, UNION operators, or boolean logic) inside the _search or _search_params parameters, the attacker bypasses application-level validation. Since the application dynamically constructs SQL queries using these parameters, the database executes the injected payload. This enables unauthorized extraction of sensitive data, including user credentials, session tokens, and email contents.
3. Infrastructure & Business Impact
With a CVSS score of 9.8 (Critical) and its inclusion in the CISA KEV (Known Exploited Vulnerabilities) catalog, this vulnerability poses an active threat. Successful exploitation can lead to complete compromise of the mail server, unauthorized access to confidential corporate communications, and potential lateral movement within the internal network, causing severe reputational and operational damage.
Official Vendor Advisories & References
Roundcube before 1.3.17 and 1.4.x before 1.4.12 is prone to a potential SQL injection via search or search_params.
Frequently Asked SecOps Questions (CVE-2021-44026)
FAQQ1. How critical is CVE-2021-44026 and is it actively exploited in the wild?
CVE-2021-44026 is rated CVSS 9.8 (CRITICAL) with a 30-day EPSS exploitation probability of 69.9%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.
Q2. Which vendors and products are affected by CVE-2021-44026?
Primary impacted vendors include roundcube across roundcubemail. Scope summary: Roundcube Webmail versions prior to 1.3.17 and 1.4.x versions prior to 1.4.12
Q3. What temporary mitigations or workarounds exist for CVE-2021-44026 before patching?
[Mitigation] Immediately upgrade Roundcube to the latest stable releases (1.3.17, 1.4.12, or higher) Follow the CLI remediation commands and interactive SecOps checklist on this page to restrict exposure prior to your maintenance window.
Generate an Internal Engineering Notice or CISO Report for CVE-2021-44026
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