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Fencer Vulns
medium 6.5

CVE-2025-52955 json

Junos OS and Junos OS Evolved: When jflow/sflow is configured continuous logical interface flaps causes rpd crash and restart

published 2025-07-11 15 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-21163

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits
0
none known

Summary

An Incorrect Calculation of Buffer Size vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a memory corruption that leads to a rpd crash.

When the logical interface using a routing instance flaps continuously, specific updates are sent to the jflow/sflow modules. This results in memory corruption, leading to an rpd crash and restart.

Continued receipt of these specific updates will cause a sustained Denial of Service condition.

This issue affects Junos OS:

* All versions before 21.2R3-S9, * All versions of 21.4, * All versions of 22.2, * from 22.4 before 22.4R3-S7, * from 23.2 before 23.2R2-S3, * from 23.4 before 23.4R2-S4, * from 24.2 before 24.2R2.

Junos OS Evolved:

* All versions of 21.2-EVO,  * All versions of 21.4-EVO,  * All versions of 22.2-EVO,  * from 22.4 before 22.4R3-S7-EVO,  * from 23.2 before 23.2R2-S3-EVO,  * from 23.4 before 23.4R2-S4-EVO,  * from 24.2 before 24.2R2-EVO.

Patch / fix

  • Juniper Networks Junos OS 21.2R3-S9, 22.4R3-S7, 23.2R2-S3, 23.4R2-S4, 24.2R2
  • Juniper Networks Junos OS Evolved 22.4R3-S7-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
15 mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 7.1 CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/R:A/U:Green
CNA 4.0 7.1 CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:A/V:X/RE:X/U:Green

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved

Classification

Weakness
  • CWE-131 Incorrect Calculation of Buffer Size

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.