Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 1.42% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2021-21324High confidence
Insecure Direct Object Reference (IDOR) on "Solutions"
glpi-project · glpi
Official source article: GitHub GHSA-JVWM-GQ36-3V7V ↗. Check the applicable product and release in the original source.
6.8MediumCVSS 3.1
Within 7 days
Patch availableMedium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:High, raised one band.upgradedsince 3 Aug 2024
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs glpi-project glpi and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software auditing. In GLPI before version 9.5.4 there is an Insecure Direct Object Reference (IDOR) on "Solutions". This vulnerability gives an unauthorized user the ability to enumerate GLPI items names (including users logins) using the knowbase search form (requires authentication). To Reproduce: Perform a valid authentication at your GLPI instance, Browse the ticket list and select any open ticket, click on Solution form, then Search a solution form that will redirect you to the endpoint /"glpi/front/knowbaseitem.php?item_itemtype=Ticket&item_items_id=18&forcetab=Knowbase$1", and the item_itemtype=Ticket parameter present in the previous URL will point to the PHP alias of glpi_tickets table, so just replace it with "Users" to point to glpi_users table instead; in the same way, item_items_id=18 will point to the related column id, so changing it too you should be able to enumerate all the content which has an alias. Since such id(s) are obviously incremental, a malicious party could exploit the vulnerability simply by guessing-based attempts.
What
GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software auditing. In GLPI before version 9.5.4 there is an Insecure Direct Object Reference (IDOR) on "Solutions". This vulnerability gives an unauthorized user the ability to enumerate GLPI items names (including users logins) using the knowbase search form (requires authentication). To Reproduce: Perform a valid authentication at your GLPI instance, Browse the ticket list and select any open ticket, click on Solution form, then Search a solution form that will redirect you to the endpoint /"glpi/front/knowbaseitem.php?item_itemtype=Ticket&item_items_id=18&forcetab=Knowbase$1", and the item_itemtype=Ticket parameter present in the previous URL will point to the PHP alias of glpi_tickets table, so just replace it with "Users" to point to glpi_users table instead; in the same way, item_items_id=18 will point to the related column id, so changing it too you should be able to enumerate all the content which has an alias. Since such id(s) are obviously incremental, a malicious party could exploit the vulnerability simply by guessing-based attempts.
Why
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
GLPI is an open-source asset and IT management software package that provides ITIL Service Desk features, licenses tracking and software auditing. In GLPI before version 9.5.4 there is an Insecure Direct Object Reference (IDOR) on "Solutions". This vulnerability gives an unauthorized user the ability to enumerate GLPI items names (including users logins) using the knowbase search form (requires authentication). To Reproduce: Perform a valid authentication at your GLPI instance, Browse the ticket list and select any open ticket, click on Solution form, then Search a solution form that will redirect you to the endpoint /"glpi/front/knowbaseitem.php?item_itemtype=Ticket&item_items_id=18&forcetab=Knowbase$1", and the item_itemtype=Ticket parameter present in the previous URL will point to the PHP alias of glpi_tickets table, so just replace it with "Users" to point to glpi_users table instead; in the same way, item_items_id=18 will point to the related column id, so changing it too you should be able to enumerate all the content which has an alias. Since such id(s) are obviously incremental, a malicious party could exploit the vulnerability simply by guessing-based attempts.
Why
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
How
An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.
- Likely attack path
- a network path → Authorization Bypass Through User-Controlled Key → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- Required interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-639 ↗
CWE-639: Authorization Bypass Through User-Controlled Key. The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:NCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- glpi: < 9.5.4
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 8 Mar 2021 · Last source change 3 Aug 2024, 18:09 UTC · CWE-639 · Authorization Bypass Through User-Controlled Key
CVE recordCVE.org · 5.1
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2021-8670
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD modified after enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.