CVE-2023-36831

CVE-2023-36831 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-703.

Key facts

Description

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.

Frequently asked questions

What is CVE-2023-36831?
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.
How severe is CVE-2023-36831?
CVE-2023-36831 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-36831 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-36831?
CVE-2023-36831 primarily affects Juniper Junos. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-36831?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2023-36831 published?
CVE-2023-36831 was published on 2023-07-14 and last updated on 2026-06-17.

References

Affected products (12)

More vulnerabilities in Juniper Junos

All CVEs affecting Juniper Junos →

Other CWE-703 vulnerabilities

Browse all CWE-703 vulnerabilities →