Junos OS: Stack-based Buffer Overflow
CVE-2024-30392 is a high-severity stack-based buffer overflow 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-S6, 21.3R3-S5, 21.4R3-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 0.69% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 21.2R3-S6 or 21.3R3-S5 or 21.4R3-S5 or 22.1R3-S3, whichever matches your release line, or a later version.
- Update Junos to 21.2 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-S6; 21.3 up to, but not including, 21.3R3-S5; 21.4 up to, but not including, 21.4R3-S5; 22.1 up to, but not including, 22.1R3-S3; 22.2 up to, but not including, 22.2R3-S1; 22.3 up to, but not including, 22.3R2-S2, 22.3R3; 22.4 up to, but not including, 22.4R2-S1, 22.4R3; before 21.2r3-s6; and 8 more ranges | 21.2R3-S6, 21.3R3-S5, 21.4R3-S5, 22.1R3-S3, 22.2R3-S1, 22.3R2-S2, 22.3R3 |
| Juniper Networks | Junos | before 21.2; 21.2; 21.3; 21.4; 22.1; 22.2; 22.3; 22.4 | 21.2 |
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
A Stack-based Buffer Overflow vulnerability in Flow Processing Daemon (flowd) of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to cause Denial of Service (DoS). On all Junos OS MX Series platforms with SPC3 and MS-MPC/-MIC, when URL filtering is enabled and a specific URL request is received and processed, flowd will crash and restart. Continuous reception of the specific URL request will lead to a sustained Denial of Service (DoS) condition. This issue affects: Junos OS: * all versions before 21.2R3-S6, * from 21.3 before 21.3R3-S5, * from 21.4 before 21.4R3-S5, * from 22.1 before 22.1R3-S3, * from 22.2 before 22.2R3-S1, * from 22.3 before 22.3R2-S2, 22.3R3, * from 22.4 before 22.4R2-S1, 22.4R3.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
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 Stack-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
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