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Fencer Vulns
high 7.5

CVE-2023-36843 json

Junos OS: SRX Series: The PFE will crash on receiving malformed SSL traffic when Sky ATP is enabled

published 2023-10-12 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-40763

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

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;

Patch / fix

  • Juniper Networks Junos OS 20.4R3-S8, 21.2R3-S6, 21.3R3-S5, 21.4R3-S5, 22.1R3-S4, 22.2R3-S2, 22.3R2-S2, 22.3R3, 22.4R2-S1, 22.4R3
  • juniper_networks junos_os 20.4r3-s8, 21.1, 21.2r3-s6, 21.3r3-s5, 21.4r3-s5, 22.1r3-s2, 22.2r3-s2, 22.3r2-s2, 22.3r3, 22.4r2-s2, 22.4r3

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Juniper Networks Junos OS
  • juniper_networks junos_os

Classification

Weakness
  • CWE-168 Improper Handling of Inconsistent Special Elements

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.