CVE-2021-34718 : A vulnerability in the SSH Server process of Cisco IOS XR Software could allow a

A vulnerability in the SSH Server process of Cisco IOS XR Software could allow an authenticated, remote attacker to overwrite and read arbitrary files on the local device. This vulnerability is due to insufficient input validation of arguments that are supplied by the user for a specific file transfer method. An attacker with lower-level privileges could exploit this vulnerability by specifying Secure Copy Protocol (SCP) parameters when authenticating to a device. A successful exploit could allow the attacker to elevate their privileges and retrieve and upload files on a device that they should not have access to.

Published 2021-09-09 05:15:11

Updated 2021-09-21 20:01:31

Source Cisco Systems, Inc.

View at NVD, CVE.org

Products affected by CVE-2021-34718

Cisco » Ios Xr
Versions from including (>=) 7.4.0 and before (<) 7.4.1
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Asr 9000v-v2 » Version: N/A
When used together with: Cisco » Asr 9001 » Version: N/A
When used together with: Cisco » Asr 9006 » Version: N/A
When used together with: Cisco » Asr 9010 » Version: N/A
When used together with: Cisco » Asr 9901 » Version: N/A
When used together with: Cisco » Asr 9902 » Version: N/A
When used together with: Cisco » Asr 9903 » Version: N/A
When used together with: Cisco » Asr 9904 » Version: N/A
When used together with: Cisco » Asr 9906 » Version: N/A
When used together with: Cisco » Asr 9910 » Version: N/A
When used together with: Cisco » Asr 9912 » Version: N/A
When used together with: Cisco » Asr 9922 » Version: N/A
Cisco » Ios Xr
Versions before (<) 7.3.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Asr 9000v-v2 » Version: N/A
When used together with: Cisco » Asr 9001 » Version: N/A
When used together with: Cisco » Asr 9006 » Version: N/A
When used together with: Cisco » Asr 9010 » Version: N/A
When used together with: Cisco » Asr 9901 » Version: N/A
When used together with: Cisco » Asr 9902 » Version: N/A
When used together with: Cisco » Asr 9903 » Version: N/A
When used together with: Cisco » Asr 9904 » Version: N/A
When used together with: Cisco » Asr 9906 » Version: N/A
When used together with: Cisco » Asr 9910 » Version: N/A
When used together with: Cisco » Asr 9912 » Version: N/A
When used together with: Cisco » Asr 9922 » Version: N/A

Exploit prediction scoring system (EPSS) score for CVE-2021-34718

EPSS FAQ

0.17%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 54 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2021-34718

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
8.5	HIGH	AV:N/AC:L/Au:S/C:C/I:C/A:N	8.0	9.2	NIST
Access Vector: Network Access Complexity: Low Authentication: Single Confidentiality Impact: Complete Integrity Impact: Complete Availability Impact: None
8.1	HIGH	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N	2.8	5.2	Cisco Systems, Inc.
Attack Vector: Network Attack Complexity: Low Privileges Required: Low User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: None
8.1	HIGH	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N	2.8	5.2	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: Low User Interaction: None Scope: Unchanged Confidentiality: High Integrity: High Availability: None

CWE ids for CVE-2021-34718

CWE-88 Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')

The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
Assigned by:
- nvd@nist.gov (Primary)
- ykramarz@cisco.com (Secondary)

References for CVE-2021-34718

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-scp-inject-QwZOCv2

Vendor Advisory

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Vulnerability Details : CVE-2021-34718

Products affected by CVE-2021-34718

Exploit prediction scoring system (EPSS) score for CVE-2021-34718

CVSS scores for CVE-2021-34718

CWE ids for CVE-2021-34718

References for CVE-2021-34718