Security readout for executives and security teams
Plain-English summary
mblog 3.5.0 has a high-severity flaw where selecting a crafted theme can lead to arbitrary code execution on the server. Business urgency depends on whether the software is deployed and whether untrusted themes can reach an operator or administrator.
Executive priority
Treat this as a priority if mblog 3.5.0 is present. The impact is full server compromise, but exposure may be narrow and user interaction is required. Confirm asset presence first, then restrict theme handling and seek vendor guidance.
Technical view
The CVE describes OS command injection in mblog 3.5.0 triggered by a crafted theme when selected. CVSS 3.1 is 7.8 with local attack vector, low complexity, no privileges, required user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure appears limited to organizations running mblog 3.5.0, especially where themes can be uploaded, imported, shared, or selected from untrusted sources. The provided CVE metadata lists affected vendor and product as n/a, so asset confirmation is important.
Exploitation context
The source bundle does not show CISA KEV listing or other evidence of active exploitation. The scenario requires a crafted theme and user interaction selecting it. Public issue references exist, but the provided evidence does not establish widespread exploitation.
Researcher notes
CWE is listed as CWE-434, while the description states OS command injection. The provided affected-product metadata is incomplete. Analysis should preserve that uncertainty and focus validation on mblog 3.5.0 installations and theme-selection workflows.
Mitigation direction
- Inventory systems for mblog 3.5.0 usage.
- Avoid selecting or installing untrusted mblog themes.
- Restrict theme management to trusted administrators only.
- Check the GitHub issue and repository for vendor remediation guidance.
- Isolate affected deployments if remediation status remains unclear.
Validation and detection
- Confirm installed mblog versions on all relevant hosts.
- Review theme sources and remove unknown or untrusted themes.
- Check logs for recent theme changes or selection events.
- Look for unexpected file changes after theme activity.
- Track the CVE record and upstream issue for updates.
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-434: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-27280 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
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/langhsu/mblog/issues/44CVE reference
- https://github.com/langhsu/mblog/CVE reference
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.