How severe is CVE-2020-4020?

CVE-2020-4020 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-4020 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-4020?

CVE-2020-4020 affects Atlassian Companion. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-4020?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-4020 published?

CVE-2020-4020 was published on 2020-06-01 and last updated on 2026-06-17.

CVE-2020-4020

CVE-2020-4020 is a high-severity vulnerability in Atlassian Companion with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 7.2)
CVSS v2: 6.5
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Atlassian Companion
Published: 2020-06-01
Last modified: 2026-06-17

Description

The file downloading functionality in the Atlassian Companion App before version 1.0.0 allows remote attackers, who control a Confluence Server instance that the Companion App is connected to, execute arbitrary .exe files via a Protection Mechanism Failure.

Frequently asked questions

What is CVE-2020-4020?: The file downloading functionality in the Atlassian Companion App before version 1.0.0 allows remote attackers, who control a Confluence Server instance that the Companion App is connected to, execute arbitrary .exe files via a Protection Mechanism Failure.
How severe is CVE-2020-4020?: CVE-2020-4020 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-4020 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-4020?: CVE-2020-4020 affects Atlassian Companion. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-4020?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-4020 published?: CVE-2020-4020 was published on 2020-06-01 and last updated on 2026-06-17.

References

https://jira.atlassian.com/browse/CONFSERVER-59733

Affected products (1)

cpe:2.3:a:atlassian:companion:*:*:*:*:*:*:*:*

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