Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 1.26% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2021-22756High confidence
n/a IGSS Definition (Def.exe) V15.0.0.21140 and prior — Out-of-bounds Read
Unknown · IGSS Definition (Def.exe) V15.0.0.21140 and prior
7.8HighCVSS 3.1
Within 7 days
Patch availableHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown IGSS Definition (Def.exe) V15.0.0.21140 and prior 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.
Direct vendor intelligence
1 currentAuthoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
SEVD-2021-159-01 · CSAF 2.0 · revision 1.0.0 · finalSchneider Electric CPCERTIGSS (Interactive Graphical SCADA System)
The vendor explicitly identifies these products as affected by this CVE.
- Schneider Electric IGSS Definition (Def.exe) V15.0.0.21140 and prior
- Summary
- CWE-125: Out-of-bounds read vulnerability exists that could result in disclosure of information or remote code execution due to lack of user-supplied data validation, when a malicious CGF file is imported to IGSS Definition.
- Remediation
- Version 15.0.0.21141 of the IGSS Definition module: Def.exe includes fixes for these vulnerabilities and is available for download through IGSS Master > Update IGSS Software or here: https://igss.schneider-electric.com/igss/igssupdates/v150/IGSSUPDATE.ZIP
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
A CWE-125: Out-of-bounds read vulnerability exists inIGSS Definition (Def.exe) V15.0.0.21140 and prior that could result in disclosure of information or remote code execution due to lack of user-supplied data validation, when a malicious CGF file is imported to IGSS Definition.
What
A CWE-125: Out-of-bounds read vulnerability exists inIGSS Definition (Def.exe) V15.0.0.21140 and prior that could result in disclosure of information or remote code execution due to lack of user-supplied data validation, when a malicious CGF file is imported to IGSS Definition.
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.
What
A CWE-125: Out-of-bounds read vulnerability exists inIGSS Definition (Def.exe) V15.0.0.21140 and prior that could result in disclosure of information or remote code execution due to lack of user-supplied data validation, when a malicious CGF file is imported to IGSS Definition.
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through local access may attempt exploitation without authentication after a user interaction. If successful, the issue may execute code or commands in the affected security context.
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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- local access → Out-of-bounds Read → execute code or commands in the affected security context
- Attack surface
- Local
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Required interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-125 ↗
CWE-125: Out-of-bounds Read. The product reads data past the end, or before the beginning, of the intended buffer.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
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
- Action
- Version 15.0.0.21141 of the IGSS Definition module: Def.exe includes fixes for these vulnerabilities and is available for download through IGSS Master > Update IGSS Software or here: https://igss.schneider-electric.com/igss/igssupdates/v150/IGSSUPDATE.ZIP
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 11 Jun 2021 · Last source change 3 Aug 2024, 18:51 UTC · CWE-125 · Out-of-bounds Read
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
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-2021-9891
Product sourceVendor CSAF · Schneider Electric CPCERT
Remediation sourceVendor CSAF · Schneider Electric CPCERT
CWE sourceCNA
NVD statusNVD modified after enrichment
Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.Schneider Electric CPCERT ↗
- Before
- IGSS Definition (Def.exe) V15.0.0.21140 and prior · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- IGSS Definition (Def.exe) V15.0.0.21140 and prior · Fixed: Version 15.0.0.21141 of the IGSS Definition module: Def.exe includes fixes for these vulnerabilities and is available for download through IGSS Master > Update IGSS Software or here: https://igss.schneider-electric.com/igss/igssupdates/v150/IGSSUPDATE.ZIP
- Remediation statusRemediation status changed from Awaiting fix to Patch available.Schneider Electric CPCERT ↗
- Before
- Awaiting fix
- After
- Patch available
CVE published
Fixed release recorded from official guidance
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.