{"dataType": "CVE_RECORD", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2026-30521", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-04-02T14:37:03.326Z", "dateReserved": "2026-03-04T00:00:00.000Z", "datePublished": "2026-03-31T00:00:00.000Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-03-31T18:07:33.773Z"}, "descriptions": [{"lang": "en", "value": "A Business Logic vulnerability exists in SourceCodester Loan Management System v1.0 due to improper server-side validation. The application allows administrators to create \"Loan Plans\" with specific interest rates. While the frontend interface prevents users from entering negative numbers, this constraint is not enforced on the backend. An authenticated attacker can bypass the client-side restriction by manipulating the HTTP POST request to submit a negative value for the interest_percentage. This results in the creation of loan plans with negative interest rates."}], "affected": [{"vendor": "n/a", "product": "n/a", "versions": [{"version": "n/a", "status": "affected"}]}], "references": [{"url": "https://github.com/meifukun/Web-Security-PoCs/blob/main/Loan-Management-System/BusinessLogic-LoanPlan-NegativeInterest.md"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-602", "lang": "en", "description": "CWE-602 Client-Side Enforcement of Server-Side Security"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-04-02T14:34:20.710448Z", "id": "CVE-2026-30521", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-02T14:37:03.326Z"}}]}, "dataVersion": "5.2"}

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{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:oretnom23:loan_management_system:1.0:*:*:*:*:*:*:*", "matchCriteriaId": "7902576E-876D-4BE4-8EF6-28B7403B130D", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A Business Logic vulnerability exists in SourceCodester Loan Management System v1.0 due to improper server-side validation. The application allows administrators to create \"Loan Plans\" with specific interest rates. While the frontend interface prevents users from entering negative numbers, this constraint is not enforced on the backend. An authenticated attacker can bypass the client-side restriction by manipulating the HTTP POST request to submit a negative value for the interest_percentage. This results in the creation of loan plans with negative interest rates."}], "id": "CVE-2026-30521", "lastModified": "2026-04-02T15:16:36.773", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2026-03-31T19:16:25.753", "references": [{"source": "cve@mitre.org", "tags": ["Exploit", "Third Party Advisory"], "url": "https://github.com/meifukun/Web-Security-PoCs/blob/main/Loan-Management-System/BusinessLogic-LoanPlan-NegativeInterest.md"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-602"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "1.0"}}], "enrichment": {"confidence": 80.0, "confidence_source": "inferred", "scores": [{"score": 80.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "n/a", "source": "cna", "vendor": "n/a"}, "product": "loan_management_system", "vendor": "sourcecodester"}], "analysis": {"en": {"generated_at": "2026-04-02T22:03:26.483423+00:00", "value": {"mitigation_remediation": ["Apply the latest vendor release that enforces server\u2011side validation of interest rates.", "If no update is available, modify the backend to reject negative values for interest_percentage before persisting loan plans.", "Review all existing loan plans for negative interest rates and adjust or invalidate those entries.", "Monitor administrative actions for creation of loan plans with negative rates and investigate anomalies."], "summary": {"action": "Apply Patch", "impact": "Negative Interest Rate Creation"}, "threat_synthesis": {"affected_systems": "The vulnerability impacts SourceCodester's Loan Management System, version 1.0. Administrators of this application can create loan plans with any interest percentage due to missing server\u2011side checks.", "description_and_impact": "The vulnerability allows an authenticated user to create loan plans with negative interest rates by sending a modified POST request that circumvents client\u2011side validation. This business\u2011logic flaw lets the attacker define loan products that effectively reward borrowers or drain funds, undermining financial integrity.", "risk_and_exploitability": "The flaw carries a CVSS score of 6.5 and an EPSS score below 1\u202f%. It is not listed in the CISA KEV catalog. Exploitation requires valid administrative credentials and the ability to alter the interest_percentage field in an HTTP POST request. Successful exploitation grants the attacker the ability to create loan products with undesired negative rates, resulting in financial loss or benefit."}}}}, "created": "2026-03-31T19:56:49.791496+00:00", "title": "Business Logic Flaw Enables Negative Interest Rates in Loan Management System", "updated": "2026-04-03T09:37:58.290042+00:00", "vendors": ["sourcecodester", "sourcecodester$PRODUCT$loan_management_system"]}