Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.15% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2020
CVE-2020-3483High confidence
Duo Network Gateway (DNG) Information Disclosure Vulnerability
Cisco · Duo Network Gateway (DNG)
7.1HighCVSS 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:Medium, lowered one band.downgradedsince 13 Nov 2024
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 Cisco Duo Network Gateway (DNG) 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.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
Duo has identified and fixed an issue with the Duo Network Gateway (DNG) product in which some customer-provided SSL certificates and private keys were not excluded from logging. This issue resulted in certificate and private key information being written out in plain-text to local files on the DNG host. Any private keys logged in this way could be viewed by those with access to the DNG host operating system without any need for reversing encrypted values or similar techniques. An attacker that gained access to the DNG logs and with the ability to intercept and manipulate network traffic between a user and the DNG, could decrypt and manipulate SSL/TLS connections to the DNG and to the protected applications behind it. Duo Network Gateway (DNG) versions 1.3.3 through 1.5.7 are affected.
What
Duo has identified and fixed an issue with the Duo Network Gateway (DNG) product in which some customer-provided SSL certificates and private keys were not excluded from logging. This issue resulted in certificate and private key information being written out in plain-text to local files on the DNG host. Any private keys logged in this way could be viewed by those with access to the DNG host operating system without any need for reversing encrypted values or similar techniques. An attacker that gained access to the DNG logs and with the ability to intercept and manipulate network traffic between a user and the DNG, could decrypt and manipulate SSL/TLS connections to the DNG and to the protected applications behind it. Duo Network Gateway (DNG) versions 1.3.3 through 1.5.7 are affected.
Why
The product stores a password in plaintext within resources such as memory or 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
Duo has identified and fixed an issue with the Duo Network Gateway (DNG) product in which some customer-provided SSL certificates and private keys were not excluded from logging. This issue resulted in certificate and private key information being written out in plain-text to local files on the DNG host. Any private keys logged in this way could be viewed by those with access to the DNG host operating system without any need for reversing encrypted values or similar techniques. An attacker that gained access to the DNG logs and with the ability to intercept and manipulate network traffic between a user and the DNG, could decrypt and manipulate SSL/TLS connections to the DNG and to the protected applications behind it. Duo Network Gateway (DNG) versions 1.3.3 through 1.5.7 are affected.
Why
The product stores a password in plaintext within resources such as memory or 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 → Plaintext Storage of a Password → 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-256 ↗
CWE-256: Plaintext Storage of a Password. The product stores a password in plaintext within resources such as memory or 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:H/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.CHighConfidentiality impact: A successful attack can cause a major loss.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. - Patch available
- Fixed
- To prevent this issue, DNG administrators should upgrade to the latest version, 1.5.8, by following the upgrade instructions on the DNG page on Duo.com: https://duo.com/docs/dng#upgrading-duo-network-gateway
- Customers should search all possible locations where logs have been written to determine if certificate and/or key information has been stored in logs. Note that DNG logs are overwritten each time the DNG is restarted, potentially overwriting any logs containing this sensitive information unless they had been previously exported from the Docker container.
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 14 Oct 2020 · Last source change 13 Nov 2024, 17:51 UTC · CWE-256 · Plaintext Storage of a Password
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-2020-24754
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.