CVE-2021-34718 json
Cisco IOS XR Software Arbitrary File Read and Write Vulnerability
published 2021-09-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-21368
- cvss
- 8.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.6%
- EPSS 1.6% chance of exploitation in 30 days, percentile 75%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- cisco ios_xr 7.3.2, 7.4.1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 2 y ago
Exploit prediction
1.58% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| NVD | 2.0 | 8.5 | AV:N/AC:L/Au:S/C:C/I:C/A:N |
Affected products
- Cisco Cisco IOS XR Software
Classification
- Weakness
-
- CWE-88 Improper Neutralization of Argument Delimiters in a Command
- Technology feeds
References
Sources
- CVE List CVE-2021-34718
- NVD CVE-2021-34718
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