How severe is CVE-2020-3477?

CVE-2020-3477 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-3477 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3477?

CVE-2020-3477 affects Cisco Ios. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-3477?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-3477 published?

CVE-2020-3477 was published on 2020-09-24 and last updated on 2026-06-17.

CVE-2020-3477

CVE-2020-3477 is a medium-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Cisco Ios
Published: 2020-09-24
Last modified: 2026-06-17

Description

A vulnerability in the CLI parser of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker to access files from the flash: filesystem. The vulnerability is due to insufficient application of restrictions during the execution of a specific command. An attacker could exploit this vulnerability by using a specific command at the command line. A successful exploit could allow the attacker to obtain read-only access to files that are located on the flash: filesystem that otherwise might not have been accessible.

Frequently asked questions

What is CVE-2020-3477?: A vulnerability in the CLI parser of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, local attacker to access files from the flash: filesystem. The vulnerability is due to insufficient application of restrictions during the execution of a specific command. An attacker could exploit this vulnerability by using a specific command at the command line. A successful exploit could allow the attacker to obtain read-only access to files that are located on the flash: filesystem that otherwise might not have been accessible.
How severe is CVE-2020-3477?: CVE-2020-3477 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-3477 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3477?: CVE-2020-3477 affects Cisco Ios. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-3477?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-3477 published?: CVE-2020-3477 was published on 2020-09-24 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-info-disclosure-V4BmJBNF

Affected products (1)

cpe:2.3:o:cisco:ios:16.3.11:*:*:*:*:*:*:*

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