CVE-2023-36843 Junos OS: SRX Series: The PFE will crash on receiving malformed SSL traffic when Sky ATP is enabled
Unauthenticated attackers can crash the Packet Forwarding Engine via malformed SSL traffic if Sky ATP is enabled, requiring a manual restart.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2023-36843?
CVE-2023-36843 is a high-severity denial of service vulnerability in Juniper Junos, published on 12 Oct 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An Improper Handling of Inconsistent Special Elements vulnerability in the Junos Services Framework (jsf) module of Juniper Networks Junos OS allows an unauthenticated network based attacker to cause a crash in the Packet Forwarding Engine (pfe) and thereby resulting in a Denial of Service (DoS).
Upon receiving malformed SSL traffic, the PFE crashes. A manual restart will be needed to recover the device.
This issue only affects devices with Juniper Networks Advanced Threat Prevention (ATP) Cloud enabled with Encrypted Traffic Insights (configured via ‘security-metadata-streaming policy’).
This issue affects Juniper Networks Junos OS:
* All versions prior to 20.4R3-S8, 20.4R3-S9; * 21.1 version 21.1R1 and later versions; * 21.2 versions prior to 21.2R3-S6; * 21.3 versions prior to 21.3R3-S5; * 21.4 versions prior to 21.4R3-S5; * 22.1 versions prior to 22.1R3-S4; * 22.2 versions prior to 22.2R3-S2; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3;
Weakness: CWE-168
Which versions are affected by CVE-2023-36843?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2023-36843?
No fix has been published for CVE-2023-36843 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-36843 being exploited?
There is no known exploitation of CVE-2023-36843 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-f8h4-8cx8-j35m.