Security readout for executives and security teams
Plain-English summary
Synology File Station versions before 1.1.4-0122 had an Attachment Preview flaw that could let a logged-in attacker place malicious script or HTML in an attachment. If another user previews it, the script could run in that user's browser, risking limited data exposure or unauthorized actions in the application context.
Executive priority
Treat this as a moderate-priority hygiene fix for Synology environments. It is not documented as actively exploited in the provided sources, but outdated File Station deployments could expose user sessions or data if a malicious authenticated user can induce preview activity.
Technical view
CVE-2018-8923 is a CWE-79 cross-site scripting issue in Synology File Station Attachment Preview before 1.1.4-0122. The CVSS 3.0 score is 6.5 with network access, low complexity, low privileges, required user interaction, changed scope, and low confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to environments running Synology File Station before 1.1.4-0122 where authenticated users can upload or provide attachments that other users preview. Internet exposure increases business risk but is not stated as required beyond network reachability.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires authenticated access and another user's interaction with a malicious attachment preview, which lowers urgency compared with unauthenticated remote compromise.
Researcher notes
Key constraints are PR:L and UI:R, so validation should focus on authenticated upload or attachment paths and preview behavior. The affected range is stated only as before File Station 1.1.4-0122; do not broaden affected Synology products without vendor evidence.
Mitigation direction
- Upgrade Synology File Station to 1.1.4-0122 or later per vendor guidance.
- Review Synology advisory SA_18_09 for product-specific update instructions.
- Restrict File Station access to trusted users and trusted networks.
- Warn users not to preview unexpected attachments until systems are updated.
Validation and detection
- Inventory Synology File Station deployments and record installed versions.
- Confirm no deployment is running a version before 1.1.4-0122.
- Check whether Attachment Preview is available to untrusted authenticated users.
- Review recent suspicious attachment activity where logging is available.
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-2018-8923 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
- Medium
- CVSS
- 6.5 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
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:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L2.33.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
6.5MediumVector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://www.synology.com/zh-tw/support/security/Synology_SA_18_09CVE reference · x_refsource_CONFIRM
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.