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Fencer Vulns
high 7.5

CVE-2023-36831 json

Junos OS: SRX Series: jbuf memory leak when SSL Proxy and UTM Web-Filtering is applied

published 2023-07-14 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-40751

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

An Improper Check or Handling of Exceptional Conditions vulnerability in the UTM (Unified Threat Management) Web-Filtering feature of Juniper Networks Junos OS on SRX Series causes a jbuf memory leak to occur when accessing certain websites, eventually leading to a Denial of Service (DoS) condition. Service restoration is only possible by rebooting the system.

The jbuf memory leak only occurs in SSL Proxy and UTM Web-Filtering configurations. Other products, platforms, and configurations are not affected by this vulnerability.

This issue affects Juniper Networks Junos OS on SRX Series: 22.2 versions prior to 22.2R3; 22.3 versions prior to 22.3R2-S1, 22.3R3; 22.4 versions prior to 22.4R1-S2, 22.4R2.

This issue does not affect Juniper Networks Junos OS versions prior to 22.2R2.

Patch / fix

  • Juniper Networks Junos OS 22.2R3, 22.3R2-S1, 22.3R3, 22.4R1-S2, 22.4R2
  • juniper_networks junos_os 22.2R2, 22.2R3, 22.3R2-S1, 22.3R3, 22.4R1-S2, 22.4R2

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% 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

Affected products

  • Juniper Networks Junos OS
  • juniper_networks junos_os

Classification

Weakness
  • CWE-703 Improper Check or Handling of Exceptional Conditions

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.