Security readout for executives and security teams
Plain-English summary
GLPI deployments using the REST API could let a low-privileged attacker bypass API IP restrictions by injecting a custom header. The main business risk is unauthorized access to asset and IT management data if API access controls are trusted as a boundary.
Executive priority
Treat as a moderate-priority remediation for exposed GLPI environments, especially where GLPI stores sensitive asset, user, or operational data. Prioritize patching systems with API Rest enabled rather than organization-wide emergency response.
Technical view
CVE-2021-39213 affects GLPI versions 9.1 through before 9.5.6 when API Rest is enabled. It is a CWE-74 custom header injection issue that can bypass API IP restrictions. CVSS 3.1 is 6.8 with high confidentiality and integrity impact, high attack complexity, and low privileges required.
Likely exposure
Exposure is limited to GLPI instances running versions >= 9.1 and < 9.5.6 with API Rest enabled. Risk is higher where REST API IP restriction is relied on to protect sensitive GLPI asset or operational data.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. CVSS indicates network reachability, no user interaction, low privileges required, and high attack complexity. Evidence does not support claiming broad exploitation.
Researcher notes
The source bundle identifies the affected range, required API Rest condition, CVSS vector, CWE-74 classification, fixed version, and disable-API workaround. It does not provide proof-of-concept details, exploit prevalence, or additional affected products.
Mitigation direction
- Upgrade GLPI to version 9.5.6 or later.
- Disable API Rest if immediate upgrade is not possible.
- Review vendor advisory and release notes for deployment-specific guidance.
- Reassess reliance on API IP restrictions after remediation.
Validation and detection
- Inventory GLPI versions and identify instances before 9.5.6.
- Confirm whether API Rest is enabled on each instance.
- Verify upgrade completion to GLPI 9.5.6 or later.
- Check whether compensating controls disabled API Rest where upgrade is pending.
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-74: 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 lookupCVE-2021-39213 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
- 6.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/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:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N1.65.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.8MediumVector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/glpi-project/glpi/releases/tag/9.5.6CVE reference · x_refsource_MISC
- https://github.com/glpi-project/glpi/security/advisories/GHSA-6w9f-2m6g-5777CVE 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.
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.