Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 2.42% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2022
CVE-2022-26507High confidence
A heap-based buffer overflow exists in XML Decompression DecodeTreeBlock in AT&T Labs Xmill 0.7
Unknown · Unknown
9.8CriticalCVSS 3.1
Within 72 hours
Patch availableCritical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Unknown 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-2021-222-02 · CSAF 2.0 · revision 4.0.0 · finalSchneider Electric CPCERTAT&T Labs Compressor (XMilI) and Decompressor (XDemill) used by EcoStruxureTM Control Expert, EcoStruxureTM Process Expert and SCADAPack RemoteConnect™ for x70
The vendor explicitly identifies these products as affected by this CVE.
- Schneider Electric EcoStruxure™ Control Expert <15.1 HF001
- Schneider Electric EcoStruxure™ Process Expert <2021
- Schneider Electric SCADAPack RemoteConnect™ for x70 <R2.7.3
- Summary
- The vulnerabilities reported on XDemill and XMilI are triggered through the execution of a malicious script on the engineering workstation, or when loading a specially crafted project file into the engineering tool. The successful exploitation of these vulnerabilities may lead to code execution with elevated privileges on the engineering workstation.
- Remediation
- V15.1 HF001 of EcoStruxure™ Control Expert includes a fix for these vulnerabilities and is available for download here: https://www.se.com/ww/en/download/document/ControlExpert_V151_HF001/ If customers choose not to apply the remediation provided above, they should immediately apply the following mitigations to reduce the risk of exploit: • Store the project files in a secure storage and restrict the access to only trusted users • When exchanging files over the network, use secure communication channels • Only open project files received from a trusted source • Compute a hash of the project files and regularly check the consistency of this hash to verify the integrity before usage • Harden the workstation running EcoStruxure Control Expert or Unity Pro • Customers using Unity Pro should strongly consider migrating to EcoStruxure Control Expert.
Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.
Patch available01
What, why and how
A heap-based buffer overflow exists in XML Decompression DecodeTreeBlock in AT&T Labs Xmill 0.7. A crafted input file can lead to remote code execution. This is not the same as any of: CVE-2021-21810, CVE-2021-21811, CVE-2021-21812, CVE-2021-21815, CVE-2021-21825, CVE-2021-21826, CVE-2021-21828, CVE-2021-21829, or CVE-2021-21830. NOTE: This vulnerability only affects products that are no longer supported by the maintainer
What
A heap-based buffer overflow exists in XML Decompression DecodeTreeBlock in AT&T Labs Xmill 0.7. A crafted input file can lead to remote code execution. This is not the same as any of: CVE-2021-21810, CVE-2021-21811, CVE-2021-21812, CVE-2021-21815, CVE-2021-21825, CVE-2021-21826, CVE-2021-21828, CVE-2021-21829, or CVE-2021-21830. NOTE: This vulnerability only affects products that are no longer supported by the maintainer
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
What
A heap-based buffer overflow exists in XML Decompression DecodeTreeBlock in AT&T Labs Xmill 0.7. A crafted input file can lead to remote code execution. This is not the same as any of: CVE-2021-21810, CVE-2021-21811, CVE-2021-21812, CVE-2021-21815, CVE-2021-21825, CVE-2021-21826, CVE-2021-21828, CVE-2021-21829, or CVE-2021-21830. NOTE: This vulnerability only affects products that are no longer supported by the maintainer
Why
A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.
How
An attacker operating through a network path may attempt exploitation without authentication or 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
- a network path → Out-of-bounds Write → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- 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-787 ↗
CWE-787: Out-of-bounds Write. The product writes 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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCommon 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.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.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
- Affected
- Fixed
- Action
- V15.1 HF001 of EcoStruxure™ Control Expert includes a fix for these vulnerabilities and is available for download here: https://www.se.com/ww/en/download/document/ControlExpert_V151_HF001/ If customers choose not to apply the remediation provided above, they should immediately apply the following mitigations to reduce the risk of exploit: • Store the project files in a secure storage and restrict the access to only trusted users • When exchanging files over the network, use secure communication channels • Only open project files received from a trusted source • Compute a hash of the project files and regularly check the consistency of this hash to verify the integrity before usage • Harden the workstation running EcoStruxure Control Expert or Unity Pro • Customers using Unity Pro should strongly consider migrating to EcoStruxure Control Expert.
- Workaround
- A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04
Evidence and provenance
Published 14 Apr 2022 · Last source change 3 Aug 2024, 05:03 UTC · CWE-787 · Out-of-bounds Write
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-2022-31065
Product sourceVendor CSAF · Schneider Electric CPCERT
Remediation sourceVendor CSAF · Schneider Electric CPCERT
CWE sourceNIST NVD
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
- n/a · Fixed: No fixed version is explicitly recorded in the structured CVE data.
- After
- n/a · Fixed: V15.1 HF001 of EcoStruxure™ Control Expert includes a fix for these vulnerabilities and is available for download here: https://www.se.com/ww/en/download/document/ControlExpert_V151_HF001/ If customers choose not to apply the remediation provided above, they should immediately apply the following mitigations to reduce the risk of exploit: • Store the project files in a secure storage and restrict the access to only trusted users • When exchanging files over the network, use secure communication channels • Only open project files received from a trusted source • Compute a hash of the project files and regularly check the consistency of this hash to verify the integrity before usage • Harden the workstation running EcoStruxure Control Expert or Unity Pro • Customers using Unity Pro should strongly consider migrating to EcoStruxure Control Expert.
- Remediation statusRemediation status changed from Mitigation available to Patch available.Schneider Electric CPCERT ↗
- Before
- Mitigation available
- After
- Patch available
CVE published
Mitigation reference recorded
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.