Security readout for executives and security teams
Plain-English summary
Synology Safe Access before 1.2.3-0234 has multiple XSS flaws that could let an attacker inject script or HTML into trusted management views. The issue is high severity, but the CVSS vector indicates high privileges and user interaction are required.
Executive priority
Treat this as a near-term remediation item for Synology environments. The business risk is highest where Safe Access administration is exposed or broadly delegated, because successful XSS could affect trusted users and sensitive management workflows.
Technical view
CVE-2020-27659 is CWE-79 cross-site scripting in Synology Safe Access. The reported injection points are the domain and profile parameters. CVSS 3.1 is 8.4 with network access, low complexity, high privileges required, user interaction required, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to environments running Synology Safe Access versions before 1.2.3-0234. Systems with administrative or privileged Safe Access users and web-accessible management surfaces should be prioritized for inventory and update checks.
Exploitation context
The bundle does not show CISA KEV listing or confirmed active exploitation. Public vendor and research references exist, but the provided evidence supports vulnerability existence, not current exploitation in the wild.
Researcher notes
Validate only version exposure and reachable administrative surfaces. The CVSS vector indicates PR:H and UI:R, so testing assumptions should include privileged attacker context and victim interaction without moving into exploit reproduction.
Mitigation direction
- Update Synology Safe Access to 1.2.3-0234 or later.
- Review Synology advisory SA-20:25 for product-specific guidance.
- Restrict administrative access to trusted networks and users.
- Review privileged Safe Access accounts for least-privilege configuration.
Validation and detection
- Inventory Synology devices running Safe Access.
- Confirm installed Safe Access version is 1.2.3-0234 or later.
- Check whether Safe Access management is reachable from untrusted networks.
- Review logs for suspicious privileged web activity around Safe Access.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-27659 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H1.76Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.4HighVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.synology.com/security/advisory/Synology_SA_20_25CVE reference · x_refsource_CONFIRM
- https://www.talosintelligence.com/vulnerability_reports/TALOS-2020-1087CVE reference · x_refsource_MISC
- https://github.com/thomasfady/Synology_SA_20_25CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.