CVE-2020-3204 json
Cisco IOS and IOS XE Software Tcl Arbitrary Code Execution Vulnerability
published 2020-06-03 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-24475
- cvss
- 6.7
- version 3.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
A vulnerability in the Tool Command Language (Tcl) interpreter of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker with privileged EXEC credentials to execute arbitrary code on the underlying operating system (OS) with root privileges. The vulnerability is due to insufficient input validation of data passed to the Tcl interpreter. An attacker could exploit this vulnerability by loading malicious Tcl code on an affected device. A successful exploit could allow the attacker to cause memory corruption or execute the code with root privileges on the underlying OS of the affected device.
Patch / fix
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 23 mo ago
Exploit prediction
0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.0 | 6.7 | CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 6.7 | CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.2 | AV:L/AC:L/Au:N/C:C/I:C/A:C |
Affected products
- Cisco Cisco IOS 12.2(53)SE1
Classification
- Weakness
-
- CWE-20 Improper Input Validation
- Technology feeds
References
-
tools.cisco.com
/security/center/content/CiscoSecurityAdvisory/cisco-sa-tcl-ace-C9KuVKmm
vendor-advisory, patch
Sources
- CVE List CVE-2020-3204
- NVD CVE-2020-3204
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