CVE-2020-18662

published 2021-06-24

CVE-2020-18662: SQL Injection vulnerability in gnuboard5 <=v5.3.2.8 via the table_prefix parameter in install_db.php.

Priority P2 61 critical 9.8 CVSS 3.1

AV N AC L PR N UI N S U C H I H A H

EXPLOIT

SQL Injection vulnerability in gnuboard5 <=v5.3.2.8 via the table_prefix parameter in install_db.php.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
sir	gnuboard	<= 5.3.2.8	—

Detection & IOCs extracted from sources · hover to see the quote

url /install/install_db.php↗

command table_prefix=12`; select sleep(5)#↗

command table_prefix=' OR 1=1--↗

• → Monitor POST requests to /install/install_db.php — this installation endpoint should not be publicly accessible post-install and any POST to it is suspicious. ↗
• → Inspect the `table_prefix` POST parameter for SQL injection payloads, including backtick-terminated statements, sleep-based blind SQLi, and OR-based boolean payloads. ↗
• → Detect time-based blind SQL injection attempts by alerting on anomalous response delays (≥5s) correlated with POST requests to install_db.php containing SQL keywords (sleep, select) in the table_prefix parameter. ↗
• → Content-Type: application/x-www-form-urlencoded is used in the exploit; correlate with the target path and suspicious table_prefix values for WAF/IDS rules. ↗

• · The vulnerable endpoint install_db.php is part of the installation workflow; if the install directory is removed or access-restricted after setup (as is best practice), the attack surface is eliminated. Verify whether the /install/ directory is still present and accessible on deployed instances. ↗

CVSS provenance

nvd v3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd v2.0 7.5 HIGH AV:N/AC:L/Au:N/C:P/I:P/A:P

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