Security readout for executives and security teams
CVE-2021-39136 is a high-severity cross-site scripting flaw in baserCMS file upload handling. A lower-privileged CMS user could cause script execution in a management-system context if user interaction occurs, risking data exposure or unauthorized actions. The sources advise upgrading and state no workaround is available. Exposure is limited to organizations running baserCMS before 4.5.1. Risk is most relevant where CMS management functions are reachable and users with upload permissions exist. The provided sources do not identify other affected products or CPEs. Treat this as a priority remediation for any baserCMS deployment. It is not described as actively exploited, but the high CVSS score and lack of workaround mean upgrade status should be confirmed quickly. Mitigation focus: Upgrade baserCMS to version 4.5.1 or later.; Confirm production, staging, and backup instances are not running versions before 4.5.1.; Use vendor and JVN advisories for any additional operational guidance..
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
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ATT&CK lookup starting points
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CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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 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-2021-39136 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
- 8.7 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
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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:L/UI:R/S:C/C:H/I:H/A:N2.35.8Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.7HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/baserproject/basercms/security/advisories/GHSA-hgjr-632x-qpp3CVE reference · x_refsource_CONFIRM
- https://github.com/baserproject/basercms/commit/568d4cab5ba1cdee7bbf0133c676d02a98f6d7bcCVE reference · x_refsource_MISC
- https://basercms.net/security/JVN_14134801CVE reference · x_refsource_MISC
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 Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.