Security readout for executives and security teams
Plain-English summary
This CVE is a cross-site scripting issue in Synology DSM’s info.cgi page. A logged-in attacker could place malicious script or HTML through the host parameter and rely on a user interaction to make it run. Business impact is moderate: affected NAS administration interfaces could be abused to mislead users or affect confidentiality, integrity, and availability at a low level.
Executive priority
Prioritize remediation for any internet-accessible or shared-user DSM systems. This is not supported as actively exploited in the provided sources, but it affects administrative web surfaces and has a vendor-fixed version, making patch validation a reasonable near-term task.
Technical view
CVE-2018-8917 is CWE-79 in Synology DiskStation Manager before 6.1.6-15266. The vulnerable component is info.cgi, where the host parameter allows arbitrary web script or HTML injection. CVSS 3.0 is 6.5 with AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L, indicating network reachability, low complexity, required privileges, and required user interaction.
Likely exposure
Exposure is limited to Synology DSM deployments running versions before 6.1.6-15266. Risk is higher where DSM management surfaces are reachable from untrusted networks or where low-privilege accounts exist. The source bundle does not provide exact CPEs or a full affected version matrix.
Exploitation context
The provided sources do not show CISA KEV listing or active exploitation. The CVSS vector indicates exploitation requires network access, low privileges, and user interaction. Treat internet-exposed DSM management interfaces as higher operational concern, but do not assume known exploitation from this bundle alone.
Researcher notes
The strongest evidence is the CVE description and Synology advisory reference. The affected entry is broad and lacks CPEs. Do not expand scope beyond Synology DSM before 6.1.6-15266 without vendor confirmation. Validate exposure through version inventory and management-interface reachability, not exploit reproduction.
Mitigation direction
- Upgrade Synology DSM to 6.1.6-15266 or later per vendor guidance.
- Review Synology advisory Synology_SA_18_14 for product-specific remediation details.
- Restrict DSM management access to trusted networks or VPN users.
- Remove unnecessary low-privilege DSM accounts where operationally feasible.
- Monitor DSM web access logs for suspicious requests to info.cgi.
Validation and detection
- Inventory Synology DSM systems and record installed DSM versions.
- Confirm no DSM instance is running below 6.1.6-15266.
- Check whether DSM administration is exposed to the internet.
- Review account lists for unnecessary low-privilege access.
- Verify security monitoring covers DSM web management activity.
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-2018-8917 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/security/advisory/Synology_SA_18_14CVE 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.