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CVE-2018-9230: Openresty: Improper Neutralization of Special Elements used in an SQL Command

CVE-2018-9230 is rated critical with a CVSS v3.0 base score of 9.8 and affects Openresty. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

In OpenResty through 1.13.6.1, URI parameters are obtained using the ngx.req.get_uri_args and ngx.req.get_post_args functions that ignore parameters beyond the hundredth one, which might allow remote attackers to bypass intended access restrictions or interfere with certain Web Application Firewall (ngx_lua_waf or X-WAF) products. NOTE: the vendor has reported that 100 parameters is an intentional default setting, but is adjustable within the API. The vendor's position is that a security-relevant misuse of the API by a WAF product is a vulnerability in the WAF product, not a vulnerability in OpenResty

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-89: Improper Neutralization of Special Elements used in an SQL Command

The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.

Affected products

  • Openresty: before 1.13.6.1

References