CVE-2019-16667

published 2019-09-26

CVE-2019-16667: diag_command.php in pfSense 2.4.4-p3 allows CSRF via the txtCommand or txtRecallBuffer field, as demonstrated by executing OS commands. This occurs because…

Priority P2 69 high 8.8 CVSS 3.1

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

EXPLOIT

diag_command.php in pfSense 2.4.4-p3 allows CSRF via the txtCommand or txtRecallBuffer field, as demonstrated by executing OS commands. This occurs because csrf_callback() produces a "CSRF token expired" error and a Try Again button when a CSRF token is missing.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
netgate	pfsense	—	—

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

path /diag_command.php↗

• → Monitor HTTP POST requests to /diag_command.php that are missing a valid CSRF token (i.e., requests where the CSRF token field is absent or tampered), especially those containing shell metacharacters or pipe-chained commands in the txtCommand or txtRecallBuffer parameters. ↗
• → The exploit's two-stage flow produces a 'CSRF token expired' intermediate response followed by a second POST (Try Again button click) that executes the payload. Correlate two rapid sequential POSTs to /diag_command.php from the same session as a high-fidelity indicator. ↗

CVSS provenance

nvd v3.1 8.8 HIGH CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

nvd v2.0 6.8 MEDIUM AV:N/AC:M/Au:N/C:P/I:P/A:P

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