Security readout for executives and security teams
Plain-English summary
Synology DSM systems before 6.2.3-25426-3 have a Security Advisor report-management flaw that can let a remote attacker read arbitrary files. The main business risk is unauthorized disclosure of sensitive data stored on or accessible from the NAS. The sources do not show active exploitation.
Executive priority
Treat this as a high-priority confidentiality issue for Synology NAS environments. Patch or isolate exposed DSM systems promptly, with highest urgency for devices reachable from the internet or partner networks.
Technical view
CVE-2021-29084 is a CWE-74 injection issue in Synology DSM Security Advisor report management. The CVSS 3.1 vector is network-accessible, low complexity, no privileges, no user interaction, with high confidentiality impact only. The attack vector is described as unspecified.
Likely exposure
Exposure is likely limited to Synology DiskStation Manager deployments running versions before 6.2.3-25426-3, especially where DSM services are reachable from untrusted networks or the internet.
Exploitation context
The source bundle does not identify public exploit code, real-world exploitation, or CISA KEV listing. Because vectors are unspecified, assess risk by product version and network exposure rather than by reproducing the issue.
Researcher notes
Evidence supports arbitrary file read in DSM Security Advisor report management before 6.2.3-25426-3. The sources do not provide attack details, affected CPEs, or exploitation evidence. Validation should focus on asset versioning, reachability, and vendor advisory alignment.
Mitigation direction
- Upgrade affected Synology DSM systems to 6.2.3-25426-3 or later where applicable.
- Review Synology advisory Synology_SA_20_26 for branch-specific vendor guidance.
- Restrict DSM management access to trusted networks and authenticated administrative paths.
- Prioritize internet-facing or third-party-reachable DSM systems first.
Validation and detection
- Inventory Synology DSM assets and record exact DSM versions.
- Flag DSM versions earlier than 6.2.3-25426-3 as potentially affected.
- Confirm whether DSM interfaces are reachable from untrusted networks.
- Review update status against Synology_SA_20_26 before closing remediation.
- Avoid exploit-based validation because the public vector is unspecified.
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-74: 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-2021-29084 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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:N/UI:N/S:U/C:H/I:N/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.synology.com/security/advisory/Synology_SA_20_26CVE 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 Special Elements in Output Used by a Downstream Component ('Injection')
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.