How severe is CVE-2020-27656?

CVE-2020-27656 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2020-27656 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27656?

CVE-2020-27656 affects Synology Diskstation Manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27656?

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

When was CVE-2020-27656 published?

CVE-2020-27656 was published on 2020-10-29 and last updated on 2026-06-17.

CVE-2020-27656

CVE-2020-27656 is a medium-severity vulnerability in Synology Diskstation Manager with a CVSS 3.x base score of 6.5. 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-319.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-319
Affected product: Synology Diskstation Manager
Published: 2020-10-29
Last modified: 2026-06-17

Description

Cleartext transmission of sensitive information vulnerability in DDNS in Synology DiskStation Manager (DSM) before 6.2.3-25426-2 allows man-in-the-middle attackers to eavesdrop authentication information of DNSExit via unspecified vectors.

Frequently asked questions

What is CVE-2020-27656?: Cleartext transmission of sensitive information vulnerability in DDNS in Synology DiskStation Manager (DSM) before 6.2.3-25426-2 allows man-in-the-middle attackers to eavesdrop authentication information of DNSExit via unspecified vectors.
How severe is CVE-2020-27656?: CVE-2020-27656 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2020-27656 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27656?: CVE-2020-27656 affects Synology Diskstation Manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27656?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-27656 published?: CVE-2020-27656 was published on 2020-10-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:synology:diskstation_manager:*:*:*:*:*:*:*:*

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