Junos OS: Improper Handling of Exceptional Conditions
CVE-2024-39547 is a high-severity improper handling of exceptional conditions vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 21.2R3-S8, 21.4R3-S7, 22.1R3-S6 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.97% chance of exploitation within 30 days, higher than 62% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 21.2R3-S8 or 21.4R3-S7 or 22.1R3-S6 or 22.2R3-S4, whichever matches your release line, or a later version.
- Update Junos OS Evolved to 21.4R3-S7-EVO or 22.2R3-S4-EVO or 22.3R3-S3-EVO or 22.4R3-S2-EVO, whichever matches your release line, or a later version.
- Update junos to 21.2r3-s8 or 21.4r3-s7 or 22.1r3-s6 or 22.2r3-s4, whichever matches your release line, or a later version.
- Read the advisory on supportportal.juniper.net for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Juniper Networks | Junos OS | before 21.2R3-S8; 21.4 up to, but not including, 21.4R3-S7; 22.1 up to, but not including, 22.1R3-S6; 22.2 up to, but not including, 22.2R3-S4; 22.3 up to, but not including, 22.3R3-S3; 22.4 up to, but not including, 22.4R3-S2; 23.2 up to, but not including, 23.2R2-S2; 24.2 up to, but not including, 24.2R2 | 21.2R3-S8, 21.4R3-S7, 22.1R3-S6, 22.2R3-S4, 22.3R3-S3, 22.4R3-S2 |
| Juniper Networks | Junos OS Evolved | before 21.4R3-S7-EVO; 22.2-EVO up to, but not including, 22.2R3-S4-EVO; 22.3-EVO up to, but not including, 22.3R3-S3-EVO; 22.4-EVO up to, but not including, 22.4R3-S2-EVO; 23.2-EVO up to, but not including, 23.2R2-EVO | 21.4R3-S7-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO, 22.4R3-S2-EVO, 23.2R2-EVO |
| Juniper Networks | junos | before 21.2r3-s8; 21.4 up to, but not including, 21.4r3-s7; 22.1 up to, but not including, 22.1r3-s6; 22.2 up to, but not including, 22.2r3-s4; 22.3 up to, but not including, 22.3r3-s3; 22.4 up to, but not including, 22.4r3-s2; 23.2 up to, but not including, 23.2r2-s2; 24.2 up to, but not including, 24.2r2 | 21.2r3-s8, 21.4r3-s7, 22.1r3-s6, 22.2r3-s4, 22.3r3-s3, 22.4r3-s2 |
| Juniper Networks | junos_evolved | before 21.4r3-s7-evo; 22.2-evo up to, but not including, 22.2r3-s4-evo; 22.3-evo up to, but not including, 22.3r3-s3-evo; 22.4-evo up to, but not including, 22.4r3-s2-evo; 23.2-evo up to, but not including, 23.2r2-evo | 21.4r3-s7-evo, 22.2r3-s4-evo, 22.3r3-s3-evo, 22.4r3-s2-evo, 23.2r2-evo |
| Juniper Networks | Junos Containerized Routing Protocol Daemon | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA (juniper.net).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (juniper.net) |
| CVSS 3.1 | 7.5 | High | CNA (juniper.net) |
Official description
An Improper Handling of Exceptional Conditions vulnerability in the rpd-server of Juniper Networks Junos OS and Junos OS Evolved within cRPD allows an unauthenticated network-based attacker sending crafted TCP traffic to the routing engine (RE) to cause a CPU-based Denial of Service (DoS). If specially crafted TCP traffic is received by the control plane, or a TCP session terminates unexpectedly, it will cause increased control plane CPU utilization by the rpd-server process. While not explicitly required, the impact is more severe when RIB sharding is enabled. Task accounting shows unexpected reads by the RPD Server jobs for shards: user@junos> show task accounting detail ... read:RPD Server.0.0.0.0+780.192.168.0.78+48886 TOT:00000003.00379787 MAX:00000000.00080516 RUNS: 233888\ read:RPD Server.0.0.0.0+780.192.168.0.78+49144 TOT:00000004.00007565 MAX:00000000.00080360 RUNS: 233888\ read:RPD Server.0.0.0.0+780.192.168.0.78+49694 TOT:00000003.00600584 MAX:00000000.00080463 RUNS: 233888\ read:RPD Server.0.0.0.0+780.192.168.0.78+50246 TOT:00000004.00346998 MAX:00000000.00080338 RUNS: 233888\ This issue affects: Junos OS with cRPD: * All versions before 21.2R3-S8, * 21.4 before 21.4R3-S7, * 22.1 before 22.1R3-S6, * 22.2 before 22.2R3-S4, * 22.3 before 22.3R3-S3, * 22.4 before 22.4R3-S2, * 23.2 before 23.2R2-S2, * 24.2 before 24.2R2; Junos OS Evolved with cRPD: * All versions before 21.4R3-S7-EVO, * 22.2 before 22.2R3-S4-EVO, * 22.3 before 22.3R3-S3-EVO, * 22.4 before 22.4R3-S2-EVO, * 23.2 before 23.2R2-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Exceptional Conditions
The product does not handle or incorrectly handles an exceptional condition.
More Improper Handling of Exceptional Conditions vulnerabilities (CWE-755)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Junos OS
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
Recent Improper Handling of Exceptional Conditions vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
- 7.8 High severity
- 8.8 High severity
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