Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.33% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2020-26941High confidence
The possibility of exploiting this vulnerability is limited and can only take place during the installation phase of ESET products
Unknown · Unknown
5.5MediumCVSS 3.1
Scheduled
Fix not verifiedMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Low, lowered one band.downgradedsince 4 Aug 2024
Compensating controls
- 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 Unknown and falls inside the recorded affected range.
- Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
- 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 no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Fix not verified01
What, why and how
A local (authenticated) low-privileged user can exploit a behavior in an ESET installer to achieve arbitrary file overwrite (deletion) of any file via a symlink, due to insecure permissions. The possibility of exploiting this vulnerability is limited and can only take place during the installation phase of ESET products. Furthermore, exploitation can only succeed when Self-Defense is disabled. Affected products are: ESET NOD32 Antivirus, ESET Internet Security, ESET Smart Security, ESET Smart Security Premium versions 13.2 and lower; ESET Endpoint Antivirus, ESET Endpoint Security, ESET NOD32 Antivirus Business Edition, ESET Smart Security Business Edition versions 7.3 and lower; ESET File Security for Microsoft Windows Server, ESET Mail Security for Microsoft Exchange Server, ESET Mail Security for IBM Domino, ESET Security for Kerio, ESET Security for Microsoft SharePoint Server versions 7.2 and lower.
What
A local (authenticated) low-privileged user can exploit a behavior in an ESET installer to achieve arbitrary file overwrite (deletion) of any file via a symlink, due to insecure permissions. The possibility of exploiting this vulnerability is limited and can only take place during the installation phase of ESET products. Furthermore, exploitation can only succeed when Self-Defense is disabled. Affected products are: ESET NOD32 Antivirus, ESET Internet Security, ESET Smart Security, ESET Smart Security Premium versions 13.2 and lower; ESET Endpoint Antivirus, ESET Endpoint Security, ESET NOD32 Antivirus Business Edition, ESET Smart Security Business Edition versions 7.3 and lower; ESET File Security for Microsoft Windows Server, ESET Mail Security for Microsoft Exchange Server, ESET Mail Security for IBM Domino, ESET Security for Kerio, ESET Security for Microsoft SharePoint Server versions 7.2 and lower.
Why
During installation, installed file permissions are set to allow anyone to modify those files.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
A local (authenticated) low-privileged user can exploit a behavior in an ESET installer to achieve arbitrary file overwrite (deletion) of any file via a symlink, due to insecure permissions. The possibility of exploiting this vulnerability is limited and can only take place during the installation phase of ESET products. Furthermore, exploitation can only succeed when Self-Defense is disabled. Affected products are: ESET NOD32 Antivirus, ESET Internet Security, ESET Smart Security, ESET Smart Security Premium versions 13.2 and lower; ESET Endpoint Antivirus, ESET Endpoint Security, ESET NOD32 Antivirus Business Edition, ESET Smart Security Business Edition versions 7.3 and lower; ESET File Security for Microsoft Windows Server, ESET Mail Security for Microsoft Exchange Server, ESET Mail Security for IBM Domino, ESET Security for Kerio, ESET Security for Microsoft SharePoint Server versions 7.2 and lower.
Why
During installation, installed file permissions are set to allow anyone to modify those files.
How
An attacker operating through local access 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 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 → Incorrect Default Permissions → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Local
- Privileges required
- Low: a basic authenticated account is required
- 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-276 ↗
CWE-276: Incorrect Default Permissions. During installation, installed file permissions are set to allow anyone to modify those files.
- 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:L/UI:N/S:U/C:N/I:H/A:NCommon 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.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
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. - Fix not verified
- Affected
- n/a
- Fixed
- No fixed version is explicitly recorded in the structured CVE data.
- Action
- No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 21 Jan 2021 · Last source change 4 Aug 2024, 16:03 UTC · CWE-276 · Incorrect Default Permissions
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-2020-19467
Product sourceUnavailable
Remediation sourceCVE/CNA references
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
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
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.