CVE-2023-22397

CVE-2023-22397 is a medium-severity vulnerability in Juniper Junos Os Evolved with a CVSS 3.x base score of 6.1. 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-367.

Key facts

Description

An Allocation of Resources Without Limits or Throttling weakness in the memory management of the Packet Forwarding Engine (PFE) on Juniper Networks Junos OS Evolved PTX10003 Series devices allows an adjacently located attacker who has established certain preconditions and knowledge of the environment to send certain specific genuine packets to begin a Time-of-check Time-of-use (TOCTOU) Race Condition attack which will cause a memory leak to begin. Once this condition begins, and as long as the attacker is able to sustain the offending traffic, a Distributed Denial of Service (DDoS) event occurs. As a DDoS event, the offending packets sent by the attacker will continue to flow from one device to another as long as they are received and processed by any devices, ultimately causing a cascading outage to any vulnerable devices. Devices not vulnerable to the memory leak will process and forward the offending packet(s) to neighboring devices. Due to internal anti-flood security controls and mechanisms reaching their maximum limit of response in the worst-case scenario, all affected Junos OS Evolved devices will reboot in as little as 1.5 days. Reboots to restore services cannot be avoided once the memory leak begins. The device will self-recover after crashing and rebooting. Operator intervention isn't required to restart the device. This issue affects: Juniper Networks Junos OS Evolved on PTX10003: All versions prior to 20.4R3-S4-EVO; 21.3 versions prior to 21.3R3-S1-EVO; 21.4 versions prior to 21.4R2-S2-EVO, 21.4R3-EVO; 22.1 versions prior to 22.1R1-S2-EVO, 22.1R2-EVO; 22.2 versions prior to 22.2R2-EVO. To check memory, customers may VTY to the PFE first then execute the following show statement: show jexpr jtm ingress-main-memory chip 255 | no-more Alternatively one may execute from the RE CLI: request pfe execute target fpc0 command "show jexpr jtm ingress-main-memory chip 255 | no-more" Iteration 1: Example output: Mem type: NH, alloc type: JTM 136776 bytes used (max 138216 bytes used) 911568 bytes available (909312 bytes from free pages) Iteration 2: Example output: Mem type: NH, alloc type: JTM 137288 bytes used (max 138216 bytes used) 911056 bytes available (909312 bytes from free pages) The same can be seen in the CLI below, assuming the scale does not change: show npu memory info Example output: FPC0:NPU16 mem-util-jnh-nh-size 2097152 FPC0:NPU16 mem-util-jnh-nh-allocated 135272 FPC0:NPU16 mem-util-jnh-nh-utilization 6

Frequently asked questions

What is CVE-2023-22397?
An Allocation of Resources Without Limits or Throttling weakness in the memory management of the Packet Forwarding Engine (PFE) on Juniper Networks Junos OS Evolved PTX10003 Series devices allows an adjacently located attacker who has established certain preconditions and knowledge of the environment to send certain specific genuine packets to begin a Time-of-check Time-of-use (TOCTOU) Race Condition attack which will cause a memory leak to begin. Once this condition begins, and as long as the attacker is able to sustain the offending traffic, a Distributed Denial of Service (DDoS) event occurs. As a DDoS event, the offending packets sent by the attacker will continue to flow from one device to another as long as they are received and processed by any devices, ultimately causing a cascading outage to any vulnerable devices. Devices not vulnerable to the memory leak will process and forward the offending packet(s) to neighboring devices. Due to internal anti-flood security controls and mechanisms reaching their maximum limit of response in the worst-case scenario, all affected Junos OS Evolved devices will reboot in as little as 1.5 days. Reboots to restore services cannot be avoided once the memory leak begins. The device will self-recover after crashing and rebooting. Operator intervention isn't required to restart the device. This issue affects: Juniper Networks Junos OS Evolved on PTX10003: All versions prior to 20.4R3-S4-EVO; 21.3 versions prior to 21.3R3-S1-EVO; 21.4 versions prior to 21.4R2-S2-EVO, 21.4R3-EVO; 22.1 versions prior to 22.1R1-S2-EVO, 22.1R2-EVO; 22.2 versions prior to 22.2R2-EVO. To check memory, customers may VTY to the PFE first then execute the following show statement: show jexpr jtm ingress-main-memory chip 255 | no-more Alternatively one may execute from the RE CLI: request pfe execute target fpc0 command "show jexpr jtm ingress-main-memory chip 255 | no-more" Iteration 1: Example output: Mem type: NH, alloc type: JTM 136776 bytes used (max 138216 bytes used) 911568 bytes available (909312 bytes from free pages) Iteration 2: Example output: Mem type: NH, alloc type: JTM 137288 bytes used (max 138216 bytes used) 911056 bytes available (909312 bytes from free pages) The same can be seen in the CLI below, assuming the scale does not change: show npu memory info Example output: FPC0:NPU16 mem-util-jnh-nh-size 2097152 FPC0:NPU16 mem-util-jnh-nh-allocated 135272 FPC0:NPU16 mem-util-jnh-nh-utilization 6
How severe is CVE-2023-22397?
CVE-2023-22397 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2023-22397 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-22397?
CVE-2023-22397 primarily affects Juniper Junos Os Evolved. In total, 30 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-22397?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-22397 published?
CVE-2023-22397 was published on 2023-01-13 and last updated on 2026-06-17.

References

Affected products (30)

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