Juniper Junos OS
CVE-2023-36851
Juniper Junos OS on SRX Series contains a missing authentication for critical function vulnerability that allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity. With a specific request to webauth_operation.php that doesn't require authentication, an attacker is able to upload arbitrary files via J-Web, leading to a loss of integrity for a certain part of the file system, which may allow chaining to other vulnerabilities.
What this means for your business
- It affects Juniper Junos OS. It matters if your company, or a supplier that handles your data, runs it.
- Attackers are already using it. CISA added it to its list of flaws used in real attacks on 13 November 2023.
- FIRST's prediction model gives it a 1% chance of attack attempts being seen in the next 30 days, ranking above 64% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Juniper Junos OS.
- 2If you do, follow CISA's required action below. No patch reference has been published yet.
- 3Treat it as urgent. US federal agencies must fix it by 17 November 2023. That deadline does not apply to private companies, but it shows how seriously CISA takes it.
- 4Because attackers have used it, check the affected systems for signs of a break-in, not only for the update.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CISA’s wording, unedited.
Scoring
- CVSS
- Not yet scored
Dates
- Published
- 2023-11-13
- Added to KEV
- 2023-11-13
- Remediation due
- 2023-11-17
- Sources
- CISA KEV