CVE-2023-36851

CVE-2023-36851 is a medium-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 5.3. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2023-11-13). The underlying weakness is classified as CWE-306.

Key facts

Description

A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series 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 and download arbitrary files via J-Web, leading to a loss of integrity or confidentiality, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on SRX Series: * 21.2 versions prior to 21.2R3-S8; * 21.4 versions prior to 21.4R3-S6; * 22.1 versions prior to 22.1R3-S5; * 22.2 versions prior to 22.2R3-S3; * 22.3 versions prior to 22.3R3-S2; * 22.4 versions prior to 22,4R2-S2, 22.4R3; * 23.2 versions prior to 23.2R1-S2, 23.2R2.

Frequently asked questions

What is CVE-2023-36851?
A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series 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 and download arbitrary files via J-Web, leading to a loss of integrity or confidentiality, which may allow chaining to other vulnerabilities. This issue affects Juniper Networks Junos OS on SRX Series: * 21.2 versions prior to 21.2R3-S8; * 21.4 versions prior to 21.4R3-S6; * 22.1 versions prior to 22.1R3-S5; * 22.2 versions prior to 22.2R3-S3; * 22.3 versions prior to 22.3R3-S2; * 22.4 versions prior to 22,4R2-S2, 22.4R3; * 23.2 versions prior to 23.2R1-S2, 23.2R2.
How severe is CVE-2023-36851?
CVE-2023-36851 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2023-36851 being actively exploited?
Yes. CVE-2023-36851 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2023-11-13, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2023-36851?
CVE-2023-36851 primarily affects Juniper Junos. In total, 62 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-36851?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2023-36851 have an EU (EUVD) identifier?
Yes. CVE-2023-36851 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-40771. It is also flagged as exploited in the EUVD (since 2023-11-13).
When was CVE-2023-36851 published?
CVE-2023-36851 was published on 2023-09-27 and last updated on 2026-06-17.

References

Affected products (62)

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