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Fencer Vulns
medium 6.5

CVE-2025-21593 json

Junos OS and Junos OS Evolved: On SRv6 enabled devices, an attacker sending a malformed BGP update can cause the rpd to crash

published 2025-01-09 21 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-2562

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

An Improper Control of a Resource Through its Lifetime vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker to cause a Denial-of-Service (DoS).

On devices with SRv6 (Segment Routing over IPv6) enabled, an attacker can send a malformed BGP UPDATE packet which will cause the rpd to crash and restart. Continued receipt of these UPDATE packets will cause a sustained DoS condition.

This issue affects iBGP and eBGP, and both IPv4 and IPv6 are affected by this vulnerability.This issue affects Junos OS:

* All versions before 21.2R3-S9,  * from 21.4 before 21.4R3-S10,  * from 22.2 before 22.2R3-S5,  * from 22.3 before 22.3R3-S4,  * from 22.4 before 22.4R3-S3,  * from 23.2 before 23.2R2-S2,  * from 23.4 before 23.4R2;

and Junos OS Evolved:

* All versions before 21.2R3-S9-EVO,  * from 21.4-EVO before 21.4R3-S10-EVO,  * from 22.2-EVO before 22.2R3-S5-EVO,  * from 22.3-EVO before 22.3R3-S4-EVO,  * from 22.4-EVO before 22.4R3-S3-EVO, * from 23.2-EVO before 23.2R2-S2-EVO,  * from 23.4-EVO before 23.4R2-EVO.

Patch / fix

  • Juniper Networks Junos OS 21.2R3-S9, 21.4R3-S10, 22.2R3-S5, 22.3R3-S4, 22.4R3-S3, 23.2R2-S2, 23.4R2
  • Juniper Networks Junos OS Evolved 21.2R3-S9-EVO, 21.4R3-S10-EVO, 22.2R3-S5-EVO, 22.3R3-S4-EVO, 22.4R3-S3-EVO, 23.2R2-S2-EVO, 23.4R2-EVO

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
21 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 15% 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:N/R:A
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:N/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:X

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved

Classification

Weakness
  • CWE-664 Improper Control of a Resource Through its Lifetime

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.