Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.73% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2020
CVE-2020-5425High confidence
User Impersonation possible in Tanzu SSO
VMware Tanzu · Single Sign-On for VMware Tanzu
7.9HighCVSS 3.1
Within 7 days
Fix not verifiedHigh 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
- 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 VMware Tanzu Single Sign-On for VMware Tanzu 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.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Fix not verified01
What, why and how
Single Sign-On for Vmware Tanzu all versions prior to 1.11.3 ,1.12.x versions prior to 1.12.4 and 1.13.x prior to 1.13.1 are vulnerable to user impersonation attack.If two users are logged in to the SSO operator dashboard at the same time, with the same username, from two different identity providers, one can acquire the token of the other and thus operate with their permissions. Note: Foundation may be vulnerable only if: 1) The system zone is set up to use a SAML identity provider 2) There are internal users that have the same username as users in the external SAML provider 3) Those duplicate-named users have the scope to access the SSO operator dashboard 4) The vulnerability doesn't appear with LDAP because of chained authentication.
What
Single Sign-On for Vmware Tanzu all versions prior to 1.11.3 ,1.12.x versions prior to 1.12.4 and 1.13.x prior to 1.13.1 are vulnerable to user impersonation attack.If two users are logged in to the SSO operator dashboard at the same time, with the same username, from two different identity providers, one can acquire the token of the other and thus operate with their permissions. Note: Foundation may be vulnerable only if: 1) The system zone is set up to use a SAML identity provider 2) There are internal users that have the same username as users in the external SAML provider 3) Those duplicate-named users have the scope to access the SSO operator dashboard 4) The vulnerability doesn't appear with LDAP because of chained authentication.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
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
Single Sign-On for Vmware Tanzu all versions prior to 1.11.3 ,1.12.x versions prior to 1.12.4 and 1.13.x prior to 1.13.1 are vulnerable to user impersonation attack.If two users are logged in to the SSO operator dashboard at the same time, with the same username, from two different identity providers, one can acquire the token of the other and thus operate with their permissions. Note: Foundation may be vulnerable only if: 1) The system zone is set up to use a SAML identity provider 2) There are internal users that have the same username as users in the external SAML provider 3) Those duplicate-named users have the scope to access the SSO operator dashboard 4) The vulnerability doesn't appear with LDAP because of chained authentication.
Why
The affected component does not establish the requesting party's identity reliably before granting access.
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 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 → Improper Authentication → 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
- High: exploitation depends on specific conditions
- Security boundary
- Changed: exploitation can affect a different security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-287 ↗
CWE-287: Improper Authentication. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
- 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:H/PR:L/UI:R/S:C/C:L/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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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.CLowConfidentiality impact: A successful attack can cause a limited 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
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
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
- Single Sign-On for VMware Tanzu: 1.11 < 1.11.3, 1.12 < 1.12.4, 1.13 < 1.13.1
- 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. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 31 Oct 2020 · Last source change 17 Sept 2024, 01:41 UTC · CWE-287 · Improper Authentication
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-2020-26593
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.
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.