How severe is CVE-2020-27657?

CVE-2020-27657 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-2020-27657 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27657?

CVE-2020-27657 affects Synology Router Manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27657?

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

When was CVE-2020-27657 published?

CVE-2020-27657 was published on 2020-10-29 and last updated on 2026-06-17.

CVE-2020-27657

CVE-2020-27657 is a medium-severity vulnerability in Synology Router 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% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-319
Affected product: Synology Router Manager
Published: 2020-10-29
Last modified: 2026-06-17

Description

Cleartext transmission of sensitive information vulnerability in DDNS in Synology Router Manager (SRM) before 1.2.4-8081 allows man-in-the-middle attackers to eavesdrop authentication information of DNSExit via unspecified vectors.

Frequently asked questions

What is CVE-2020-27657?: Cleartext transmission of sensitive information vulnerability in DDNS in Synology Router Manager (SRM) before 1.2.4-8081 allows man-in-the-middle attackers to eavesdrop authentication information of DNSExit via unspecified vectors.
How severe is CVE-2020-27657?: CVE-2020-27657 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-2020-27657 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27657?: CVE-2020-27657 affects Synology Router Manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27657?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-27657 published?: CVE-2020-27657 was published on 2020-10-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:synology:router_manager:*:*:*:*:*:*:*:*

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