Cisco IOS XR Software: Improper Neutralization of Special Elements used in an OS Command
CVE-2022-20655 is a high-severity improper neutralization of special elements used in an OS command vulnerability in Cisco IOS XR Software from Cisco, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.83% chance of exploitation within 30 days, higher than 58% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update ios_xr_software to 7.0.2 or 7.1.1, whichever matches your release line, or a later version.
- Update virtual_topology_system to 2.6.5 or a later version.
- Update network_services_orchestrator to 4.3.9.1 or 4.4.5.6 or 4.5.7 or 4.6.1.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco IOS XR Software | Not specified in the record | Not stated |
| Cisco | Cisco Virtual Topology System (VTS) | Not specified in the record | Not stated |
| Cisco | Cisco Network Services Orchestrator | Not specified in the record | Not stated |
| Cisco | Cisco Enterprise NFV Infrastructure Software | Not specified in the record | Not stated |
| Cisco | Cisco Catalyst SD-WAN | Not specified in the record | Not stated |
| Cisco | Cisco Catalyst SD-WAN Manager | Not specified in the record | Not stated |
| Cisco | Cisco IOS XE Catalyst SD-WAN | Not specified in the record | Not stated |
| Cisco | Cisco SD-WAN vEdge Router | Not specified in the record | Not stated |
| Cisco | Cisco Ultra Gateway Platform | Not specified in the record | Not stated |
| Cisco | Cisco Carrier Packet Transport | 3.5; 3.1; 3.2; 2.5; 2.0; 9.2.2; 1.4.0; 1.0; and 32 more ranges | Not stated |
| Cisco | ios_xr_software | before 7.0.2; 7.1.0 up to, but not including, 7.1.1 | 7.0.2, 7.1.1 |
| Cisco | virtual_topology_system | before 2.6.5 | 2.6.5 |
| Cisco | network_services_orchestrator | before 4.3.9.1; 4.4.0.0 up to, but not including, 4.4.5.6; 4.5.0 up to, but not including, 4.5.7; 4.6.0 up to, but not including, 4.6.1.7; 4.7.0 up to, but not including, 4.7.1; 5.1.0 up to, but not including, 5.1.0.1 | 4.3.9.1, 4.4.5.6, 4.5.7, 4.6.1.7, 4.7.1, 5.1.0.1 |
| Cisco | enterprise_nfv_infrastructure_software | before 3.12.1 | 3.12.1 |
| Cisco | catalyst_sd-wan_manager | before 18.4.4; 19.2.0 up to, but not including, 19.2.1 | 18.4.4, 19.2.1 |
| Cisco | ios_xe_catalyst_sd-wan | before 16.10.2; 16.12.0 up to, but not including, 16.12.1b; 17.2.0 up to, but not including, 17.2.1r | 16.10.2, 16.12.1b, 17.2.1r |
| Cisco | sd-wan_vedge_router | before 18.4.4; 19.2.0 up to, but not including, 19.2.1 | 18.4.4, 19.2.1 |
| Cisco | carrier_packet_transport | all versions | 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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official description
A vulnerability in the implementation of the CLI on a device that is running ConfD could allow an authenticated, local attacker to perform a command injection attack. The vulnerability is due to insufficient validation of a process argument on an affected device. An attacker could exploit this vulnerability by injecting commands during the execution of this process. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with the privilege level of ConfD, which is commonly root.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an OS Command
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Cisco IOS XR Software
- 7.5 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 8.2 High severity
- 8.6 High severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.9 Critical severity
- 8.8 High severity
- 9.8 Critical severity
GeoVision Devices OS Command Injection Exploited
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