Junos OS: Reachable Assertion
CVE-2023-44175 is a high-severity reachable assertion 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 20.4R3-S7, 21.1R3-S4, 21.2R3-S5 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 0.62% chance of exploitation within 30 days, higher than 50% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 20.4R3-S7 or 21.1R3-S4 or 21.2R3-S5 or 21.3R3-S4, whichever matches your release line, or a later version.
- Update Junos OS Evolved to 22.3R3-EVO or 22.4R3-EVO or 23.2R1-EVO, whichever matches your release line, or a later version.
- Update Junos to 20.4 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 20.4R3-S7; 21.1 up to, but not including, 21.1R3-S4; 21.2 up to, but not including, 21.2R3-S5; 21.3 up to, but not including, 21.3R3-S4; 21.4 up to, but not including, 21.4R3-S4; 22.1 up to, but not including, 22.1R3-S4; 22.2 up to, but not including, 22.2R3; 22.3 up to, but not including, 22.3R3; and 1 more ranges | 20.4R3-S7, 21.1R3-S4, 21.2R3-S5, 21.3R3-S4, 21.4R3-S4, 22.1R3-S4 |
| Juniper Networks | Junos OS Evolved | before 22.3R3-EVO; 22.4-EVO up to, but not including, 22.4R3-EVO; 23.2-EVO up to, but not including, 23.2R1-EVO | 22.3R3-EVO, 22.4R3-EVO, 23.2R1-EVO |
| Juniper Networks | Junos | before 20.4; 20.4; 21.2; 21.3; 21.4; 22.1; 22.2; 22.3; and 1 more ranges | 20.4 |
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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.5 | Medium | CNA (juniper.net) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
A Reachable Assertion vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows to send specific genuine PIM packets to the device resulting in rpd to crash causing a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. Note: This issue is not noticed when all the devices in the network are Juniper devices. This issue affects Juniper Networks: Junos OS: * All versions prior to 20.4R3-S7; * 21.2 versions prior to 21.2R3-S5; * 21.3 versions prior to 21.3R3-S4; * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S4; * 22.2 versions prior to 22.2R3; * 22.3 versions prior to 22.3R3; * 22.4 versions prior to 22.4R3. Junos OS Evolved: * All versions prior to 22.3R3-EVO; * 22.4-EVO versions prior to 22.4R3-EVO; * 23.2-EVO versions prior to 23.2R1-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Reachable Assertion
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
How developers prevent this class of flaw
- If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.
- Consider changing the assertion to some other less fatal error. This might not be easy to implement, since other code may be needed to handle the error.
- Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, 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 Reachable Assertion vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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