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NVD / CVE Program· CNA synology

CVE-2020-27651: Synology Router Manager (SRM) before 1.2.4-8081 does not set the Secure flag for the session cookie in an HTTPS session, which makes it…

HighCVSS 8.1 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.77% (FIRST EPSS); higher than 56.1% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • According to the record, no fixed version is available yet.
  • Severity is disputed: the assigning authority (CNA) scores it 5.8, NVD 8.1.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Synology Router Manager (SRM) before 1.2.4-8081 does not set the Secure flag for the session cookie in an HTTPS session, which makes it easier for remote attackers to capture this cookie by intercepting its transmission within an HTTP session.

Published
Oct 29, 2020
Updated
Jun 16, 2026
EPSS
0.7% · 56th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.7%

CNA vs NVD score

NVD
8.1
CNA · synology
5.8
2.3 point gap

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2020-27651

When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
synologyrouter manager

Versions reported by the vendor

Affected version ranges reported by the assigning authority (synology). Independent of NVD's CPE analysis and usually ahead of it.

  • Synology Synology Router Manager (SRM)

    • unspecified and later · before 1.2.4-8081affected

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • synology router manager1.2 and later · before 1.2.4-8081

Same product

synology: all records

Other highest-scoring records for the same primary product.

  • CVE-2020-27655Improper access control vulnerability in Synology Router Manager (SRM) before 1.2.4-8081 allows remote attackers to access restricted…
    41Plan
  • CVE-2020-27654Improper access control vulnerability in lbd in Synology Router Manager (SRM) before 1.2.4-8081 allows remote attackers to execute…
    40Plan
  • CVE-2023-32956Improper neutralization of special elements used in an OS command ('OS Command Injection') vulnerability in CGI component in Synology…
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2019-11823May 4, 2020 · CRLF injection vulnerability in Network Center in Synology Router Manager (SRM) before 1.2.3-8017-2 allows remote attackers to cause a…
    31Monitor
  • ← EarlierCVE-2020-27649Oct 29, 2020 · Improper certificate validation vulnerability in OpenVPN client in Synology Router Manager (SRM) before 1.2.4-8081 allows man-in-the-middle…
    36Monitor
  • Later →CVE-2020-27653Oct 29, 2020 · Algorithm downgrade vulnerability in QuickConnect in Synology Router Manager (SRM) before 1.2.4-8081 allows man-in-the-middle attackers to…
    33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-614 · Sensitive Cookie in HTTPS Session Without 'Secure' Attribute

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records