Security readout for executives and security teams
Plain-English summary
CVE-2020-21174 is a critical file upload flaw reported in liufee CMS v2.0.7.1. The description says a remote unauthenticated attacker could execute arbitrary code through the image suffix function. Public metadata is sparse, so treat internet-exposed deployments as urgent, but do not assume exploitation is occurring.
Executive priority
High priority for any organization running liufee CMS v2.0.7.1, especially externally. The potential impact is full system compromise, but the evidence base is limited and no active exploitation is cited in the supplied sources.
Technical view
The CVE is mapped to CWE-434 and scored CVSS 3.1 9.8 with network attack vector, low complexity, no privileges, and no user interaction. The structured affected-product metadata is incomplete, but the description names liufee CMS v2.0.7.1. No patch details are provided in the supplied sources.
Likely exposure
Exposure is most likely where liufee CMS v2.0.7.1 is deployed and its image upload functionality is reachable, especially from the internet. The CVE record’s affected fields are listed as n/a, so asset confirmation requires local inventory and application review.
Exploitation context
The sources do not show CISA KEV listing or confirmed active exploitation. The risk is still high because the CVSS vector indicates remote, unauthenticated code execution without user interaction if the vulnerable component is reachable.
Researcher notes
The key gap is incomplete affected-product and fix metadata. The GitHub issue is the primary public reference. Avoid broad product assumptions beyond liufee CMS v2.0.7.1 until maintainer evidence or local code review confirms scope.
Mitigation direction
- Check the CVE record and GitHub issue for maintainer patch or upgrade guidance.
- Inventory liufee CMS deployments and identify any v2.0.7.1 instances.
- Remove public exposure for suspected vulnerable upload functionality where feasible.
- Prioritize replacement or upgrade if maintained fixed versions are confirmed.
- Monitor web roots and upload directories for unexpected executable files.
Validation and detection
- Confirm whether liufee CMS v2.0.7.1 exists in the environment.
- Determine whether image upload functionality is enabled and externally reachable.
- Review application logs for unusual upload activity or unexpected file types.
- Check deployed code against the referenced GitHub issue details.
- Verify remediation against vendor or maintainer guidance when available.
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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-21174 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
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/liufee/cms/issues/44CVE 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.
Unrestricted Upload of File with Dangerous Type
Unrestricted Upload of File with Dangerous Type represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.