Security readout for executives and security teams
Plain-English summary
Synology Web Station before 2.1.3-0139 can be abused with a crafted URL to support phishing. The issue is not described as server takeover, but it can make deceptive links more convincing and create business risk where Web Station is internet-facing.
Executive priority
Treat this as a high-priority hygiene and phishing-risk fix for exposed Synology Web Station deployments. Prioritize public-facing systems and environments used by customers, partners, or staff for trusted communications.
Technical view
CVE-2018-8913 is a CWE-756 missing custom error page issue in Synology Web Station. The CVSS 3.0 vector is network-accessible, low complexity, no privileges required, user interaction required, scope changed, with low confidentiality, integrity, and availability impacts.
Likely exposure
Exposure is most likely where Synology Web Station versions earlier than 2.1.3-0139 are reachable by users or the internet. Systems not running Web Station are not identified as affected in the supplied sources.
Exploitation context
The provided bundle does not show CISA KEV listing or cited evidence of active exploitation. The described attack context is phishing through a crafted URL, requiring a user to interact with the link.
Researcher notes
The evidence identifies one affected product and a fixed-before boundary, but gives limited technical detail. Do not infer broader Synology NAS compromise. Validation should focus on version state, exposure, and whether error handling behaves as expected after remediation.
Mitigation direction
- Upgrade Synology Web Station to 2.1.3-0139 or later.
- Review Synology advisory Synology_SA_18_29 for vendor-specific guidance.
- Limit public exposure of Web Station where business use does not require it.
- Use phishing-resistant controls and user reporting for suspicious Synology-hosted links.
Validation and detection
- Inventory Synology devices running Web Station.
- Confirm installed Web Station versions are 2.1.3-0139 or later.
- Identify internet-facing Web Station endpoints and business owners.
- Check web error pages for branded, expected behavior after update.
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-756: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2018-8913 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
- 7.1 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/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:N/UI:R/S:C/C:L/I:L/A:L2.83.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.1HighVector: CVSS:3.0/AV:N/AC:L/PR:N/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_29CVE 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.
Missing Custom Error Page
Missing Custom Error Page represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.