Security readout for executives and security teams
Plain-English summary
Crafter CMS 3.1 has a SnakeYAML deserialization bypass where an authenticated administrator can change the main YAML configuration and load a Java class, leading to remote code execution. The source rates it medium because exploitation requires high privileges, user interaction, and high complexity.
Executive priority
Treat this as a moderate-priority remediation item. It is serious because it can result in remote code execution, but the known prerequisites are restrictive. Prioritize systems with exposed admin interfaces, weak admin controls, or high business impact.
Technical view
CVE-2021-23262 affects Crafter CMS 3.1 and is categorized as CWE-913. The CVSS 3.1 score is 4.2 with network access, high attack complexity, high privileges, required user interaction, and high availability impact. The provided sources do not name a specific patch version.
Likely exposure
Exposure appears limited to Crafter CMS 3.1 instances where administrator accounts can modify the main YAML configuration file. Organizations without Crafter CMS 3.1, or without administrator access paths to that configuration, are not indicated as affected by the provided sources.
Exploitation context
The bundle does not show CISA KEV listing or any cited active exploitation. Exploitation requires authenticated administrator privileges and interaction, so this is more relevant to compromised admin accounts, malicious insiders, or post-compromise escalation than unauthenticated internet-wide exploitation.
Researcher notes
The evidence is limited to the CVE metadata and Crafter advisory reference. Do not assume unauthenticated exploitation, broader version impact, or a confirmed patch version from this bundle alone. Focus validation on Crafter CMS 3.1, admin permissions, YAML configuration change paths, and vendor advisory status.
Mitigation direction
- Identify any Crafter CMS 3.1 deployments and their administrative exposure.
- Review Crafter’s advisory for the vendor-supported fix or upgrade path.
- Restrict administrator access to trusted users and managed networks.
- Enforce strong authentication and least privilege for CMS administrators.
- Monitor changes to the main YAML configuration file.
- Investigate unexpected Java class loading or configuration changes.
Validation and detection
- Confirm whether deployed Crafter CMS versions include 3.1.
- Review administrator account inventory and recent privilege changes.
- Check logs for main YAML configuration edits.
- Verify vendor advisory actions were applied where applicable.
- Confirm administrative interfaces are access-controlled.
- Document any compensating controls for remaining 3.1 systems.
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-913: 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 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-2021-23262 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
- 4.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/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:H/PR:H/UI:R/S:U/C:N/I:N/A:H0.53.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.2MediumVector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://docs.craftercms.org/en/3.1/security/advisory.html#cv-2021120105CVE 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 Control of Dynamically-Managed Code Resources
Improper Control of Dynamically-Managed Code Resources represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.