Security readout for executives and security teams
Plain-English summary
Synology Calendar versions before 2.3.3-0620 could expose credentials through process environment or command-line data. This is not a remote takeover issue in the provided sources, but it can reveal sensitive credentials to a local user with sufficient access.
Executive priority
Prioritize remediation for Synology systems with multiple administrators, shell access, or sensitive calendar integrations. Business urgency is moderate because exploitation is local and privileged, but exposed credentials can expand impact beyond Calendar.
Technical view
CVE-2019-11820 is a CWE-522 credential exposure flaw in Synology Calendar before 2.3.3-0620. The CVSS vector indicates local attack access, low complexity, high privileges required, user interaction required, changed scope, and high confidentiality impact only.
Likely exposure
Exposure is limited to Synology Calendar installations older than 2.3.3-0620. The provided data does not identify specific DSM versions, deployment configurations, or CPEs, so asset validation should focus on installed package version.
Exploitation context
The source bundle does not report active exploitation, and KEV status is false. The described scenario requires local access and high privileges, with credential disclosure possible through process command-line or environment exposure.
Researcher notes
The public data names Synology Calendar before 2.3.3-0620 and credential exposure via cmdline. Affected version granularity and exploit details are incomplete in the supplied bundle, so avoid assuming broader Synology product exposure.
Mitigation direction
- Update Synology Calendar to version 2.3.3-0620 or later.
- Review Synology advisory guidance for deployment-specific instructions.
- Restrict local shell and administrative access to Synology systems.
- Rotate credentials if exposure is suspected on an affected host.
Validation and detection
- Inventory Synology NAS devices running Calendar.
- Confirm installed Calendar package version is 2.3.3-0620 or later.
- Review local user and administrator access on affected systems.
- Check operational logs for unusual local access around credential use.
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-522: Credential and account abuse lookup
Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. 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-2019-11820 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
- 5.5 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:R/S:C/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:3.0/AV:L/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N1.14Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
5.5MediumVector: CVSS:3.0/AV:L/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.synology.com/security/advisory/Synology_SA_19_21CVE 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.
Insufficiently Protected Credentials
Insufficiently Protected Credentials represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.