Junos OS: Improper Handling of Exceptional Conditions
CVE-2023-36832 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 19.1R3-S10, 19.2R3-S7, 19.3R3-S8 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 0.64% chance of exploitation within 30 days, higher than 51% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 19.1R3-S10 or 19.2R3-S7 or 19.3R3-S8 or 19.4R3-S12, whichever matches your release line, or a later version.
- Update Junos to 19.1 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 19.1R3-S10; 19.2 up to, but not including, 19.2R3-S7; 19.3 up to, but not including, 19.3R3-S8; 19.4 up to, but not including, 19.4R3-S12; 20.2 up to, but not including, 20.2R3-S8; 20.4 up to, but not including, 20.4R3-S7; 21.1 up to, but not including, 21.1R3-S5; 21.2 up to, but not including, 21.2R3-S5; and 11 more ranges | 19.1R3-S10, 19.2R3-S7, 19.3R3-S8, 19.4R3-S12, 20.2R3-S8, 20.4R3-S7 |
| Juniper Networks | Junos | before 19.1; 19.1; 19.2; 19.3; 19.4; 20.2; 20.4; 21.1; and 7 more ranges | 19.1 |
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).
Official description
An Improper Handling of Exceptional Conditions vulnerability in packet processing of Juniper Networks Junos OS on MX Series allows an unauthenticated network-based attacker to send specific packets to an Aggregated Multiservices (AMS) interface on the device, causing the packet forwarding engine (PFE) to crash, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue is only triggered by packets destined to a local-interface via a service-interface (AMS). AMS is only supported on the MS-MPC, MS-MIC, and MX-SPC3 cards. This issue is not experienced on other types of interfaces or configurations. Additionally, transit traffic does not trigger this issue. This issue affects Juniper Networks Junos OS on MX Series: All versions prior to 19.1R3-S10; 19.2 versions prior to 19.2R3-S7; 19.3 versions prior to 19.3R3-S8; 19.4 versions prior to 19.4R3-S12; 20.2 versions prior to 20.2R3-S8; 20.4 versions prior to 20.4R3-S7; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S3; 22.1 versions prior to 22.1R3-S2; 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.
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
- supportportal.juniper.net/JSA71639Mitigation
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
- 7.5 High severity
- 8.2 High severity
- 7.8 High severity
- 7.7 High severity
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