An Improper Input Validation vulnerability in the Routing Protocol Daemon (rpd) of Juniper…
CVE-2023-0026 is a high-severity improper input validation 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-S8, 21.1*, 21.2R3-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 0.65% chance of exploitation within 30 days, higher than 52% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS to 20.4R3-S8 or 21.1* or 21.2R3-S6 or 21.3R3-S5, whichever matches your release line, or a later version.
- Update Junos OS Evolved to 20.4R3-S8-EVO or 21.1* or 21.2R3-S6-EVO or 21.3R3-S5-EVO, whichever matches your release line, or a later version.
- Update Junos to 20.4 or a later version.
- 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-S8; 21.1 up to, but not including, 21.1*; 21.2 up to, but not including, 21.2R3-S6; 21.3 up to, but not including, 21.3R3-S5; 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, 22.3R2-S2, 22.3R3-S1; 22.3 up to, but not including, 22.2R3-S2; and 2 more ranges | 20.4R3-S8, 21.1*, 21.2R3-S6, 21.3R3-S5, 21.4R3-S4, 22.1R3-S4 |
| Juniper Networks | Junos OS Evolved | before 20.4R3-S8-EVO; 21.1R1-EVO up to, but not including, 21.1*; 21.2 up to, but not including, 21.2R3-S6-EVO; 21.3 up to, but not including, 21.3R3-S5-EVO; 21.4 up to, but not including, 21.4R3-S4-EVO; 22.1 up to, but not including, 22.1R3-S4-EVO; 22.2 up to, but not including, 22.2R3-S2-EVO; 22.3 up to, but not including, 22.3R2-S2-EVO, 22.3R3-S1-EVO; and 2 more ranges | 20.4R3-S8-EVO, 21.1*, 21.2R3-S6-EVO, 21.3R3-S5-EVO, 21.4R3-S4-EVO, 22.1R3-S4-EVO |
| Juniper Networks | Junos | 15.1 up to, but not including, 20.4; 20.4; 21.1; 21.2; 21.3; 21.4; 22.1; 22.2; and 2 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 CNA (juniper.net).
Official description
An Improper Input Validation 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). When a BGP update message is received over an established BGP session, and that message contains a specific, optional transitive attribute, this session will be torn down with an update message error. This issue cannot propagate beyond an affected system as the processing error occurs as soon as the update is received. This issue is exploitable remotely as the respective attribute can propagate through unaffected systems and intermediate AS (if any). Continuous receipt of a BGP update containing this attribute will create a sustained Denial of Service (DoS) condition. Some customers have experienced these BGP session flaps which prompted Juniper SIRT to release this advisory out of cycle before fixed releases are widely available as there is an effective workaround. This issue affects: Juniper Networks Junos OS 15.1R1 and later versions prior to 20.4R3-S8; 21.1 version 21.1R1 and later versions prior to 21.2R3-S6; 21.3 versions prior to 21.3R3-S5; 21.4 versions prior to 21.4R3-S4; 22.1 versions prior to 22.1R3-S4; 22.2 versions prior to 22.2R3-S2; 22.3 versions prior to 22.3R2-S2, 22.3R3-S1; 22.4 versions prior to 22.4R2-S1, 22.4R3; 23.1 versions prior to 23.1R1-S1, 23.1R2. Juniper Networks Junos OS Evolved All versions prior to 20.4R3-S8-EVO; 21.1 version 21.1R1-EVO and later versions prior to 21.2R3-S6-EVO; 21.3 versions prior to 21.3R3-S5-EVO; 21.4 versions prior to 21.4R3-S4-EVO; 22.1 versions prior to 22.1R3-S4-EVO; 22.2 versions prior to 22.2R3-S2-EVO; 22.3 versions prior to 22.3R2-S2-EVO, 22.3R3-S1-EVO; 22.4 versions prior to 22.4R2-S1-EVO, 22.4R3-EVO; 23.1 versions prior to 23.1R1-S1-EVO, 23.1R2-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
How developers prevent this class of flaw
- Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
- Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
- Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
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
Other references
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 Input Validation vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 7.2 High severity
- 8.8 High severity
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