CVE-2018-0018: On SRX Series devices during compilation of IDP policies, an attacker sending specially crafted packets may be able to bypass firewall rules, leading to informa

On SRX Series devices during compilation of IDP policies, an attacker sending specially crafted packets may be able to bypass firewall rules, leading to informa

On SRX Series devices during compilation of IDP policies, an attacker sending specially crafted packets may be able to bypass firewall rules, leading to information disclosure which an attacker may use to gain control of the target device or other internal devices, systems or services protected by the SRX Series device. This issue only applies to devices where IDP policies are applied to one or more rules. Customers not using IDP policies are not affected. Depending on if the IDP updates are automatic or not, as well as the interval between available updates, an attacker may have more or less success in performing reconnaissance or bypass attacks on the victim SRX Series device or protected devices. ScreenOS with IDP is not vulnerable to this issue. Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D60 on SRX; 12.3X48 versions prior to 12.3X48-D35 on SRX; 15.1X49 versions prior to 15.1X49-D60 on SRX.

Description from the National Vulnerability Database, published by sirt@juniper.net

What it means for a small business

Junos OS is network equipment or remote-access software: the box between your office and the internet. These are a favorite target because breaking one opens the whole office.

If an IT provider set it up, ask them to confirm the firmware version and the date it was updated. If nobody looks after it, that's the bigger problem.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 1.6%, higher than 75% of CVEs. That’s above average: worth scheduling this week. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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