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 0.58% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2021-3051High confidence
Cortex XSOAR: Authentication Bypass in SAML Authentication
Palo Alto Networks · Cortex XSOAR
8.1HighCVSS 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:High, 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 Palo Alto Networks Cortex XSOAR 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
An improper verification of cryptographic signature vulnerability exists in Cortex XSOAR SAML authentication that enables an unauthenticated network-based attacker with specific knowledge of the Cortex XSOAR instance to access protected resources and perform unauthorized actions on the Cortex XSOAR server. This issue impacts: Cortex XSOAR 5.5.0 builds earlier than 1578677; Cortex XSOAR 6.0.2 builds earlier than 1576452; Cortex XSOAR 6.1.0 builds earlier than 1578663; Cortex XSOAR 6.2.0 builds earlier than 1578666. All Cortex XSOAR instances hosted by Palo Alto Networks are protected from this vulnerability; no additional action is required for these instances.
What
An improper verification of cryptographic signature vulnerability exists in Cortex XSOAR SAML authentication that enables an unauthenticated network-based attacker with specific knowledge of the Cortex XSOAR instance to access protected resources and perform unauthorized actions on the Cortex XSOAR server. This issue impacts: Cortex XSOAR 5.5.0 builds earlier than 1578677; Cortex XSOAR 6.0.2 builds earlier than 1576452; Cortex XSOAR 6.1.0 builds earlier than 1578663; Cortex XSOAR 6.2.0 builds earlier than 1578666. All Cortex XSOAR instances hosted by Palo Alto Networks are protected from this vulnerability; no additional action is required for these instances.
Why
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
An improper verification of cryptographic signature vulnerability exists in Cortex XSOAR SAML authentication that enables an unauthenticated network-based attacker with specific knowledge of the Cortex XSOAR instance to access protected resources and perform unauthorized actions on the Cortex XSOAR server. This issue impacts: Cortex XSOAR 5.5.0 builds earlier than 1578677; Cortex XSOAR 6.0.2 builds earlier than 1576452; Cortex XSOAR 6.1.0 builds earlier than 1578663; Cortex XSOAR 6.2.0 builds earlier than 1578666. All Cortex XSOAR instances hosted by Palo Alto Networks are protected from this vulnerability; no additional action is required for these instances.
Why
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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 Verification of Cryptographic Signature → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- 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-347 ↗
CWE-347: Improper Verification of Cryptographic Signature. The product does not verify, or incorrectly verifies, the cryptographic signature for data.
- 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: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.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
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
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- 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 8 Sept 2021 · Last source change 17 Sept 2024, 01:10 UTC · CWE-347 · Improper Verification of Cryptographic Signature
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-2021-26403
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.