Severity by source
AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Primary rating from GitHub Advisory.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Lifecycle Timeline
3DescriptionGitHub Advisory
Summary
Nginx-UI contains an Insecure Direct Object Reference (IDOR) vulnerability that allows any authenticated user to access, modify, and delete resources belonging to other users. The application's base Model struct lacks a user_id field, and all resource endpoints perform queries by ID without verifying user ownership, enabling complete authorization bypass in multi-user environments.
Severity
High - CVSS 3.1 Score: 8.8 (High)
Vector String: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Note: Original score was 7.5. The score was updated to 8.8 after discovering that sensitive data (DNS API tokens, ACME private keys) is stored in plaintext, which when combined with IDOR allows immediate credential theft without decryption.
Product
nginx-ui
Affected Versions
All versions up to and including v2.3.3
CWE
CWE-639: Authorization Bypass Through User-Controlled Key
Description
Exposed DNS Provider Credentials
The dns.Config structure (internal/cert/dns/config_env.go) contains API credentials:
type Configuration struct {
Credentials map[string]string `json:"credentials"` // API tokens here
Additional map[string]string `json:"additional"`
}| Provider | Credential Fields | Impact if Leaked |
|---|---|---|
| Cloudflare | CF_API_TOKEN | Full DNS zone control |
| Alibaba Cloud DNS | ALICLOUD_ACCESS_KEY, ALICLOUD_SECRET_KEY | Full DNS control + potential IAM access |
| Tencent Cloud DNS | TENCENTCLOUD_SECRET_ID, TENCENTCLOUD_SECRET_KEY | Full DNS control |
| AWS Route53 | AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY | Route53 + potential AWS access |
| GoDaddy | GODADDY_API_KEY, GODADDY_API_SECRET | DNS record modification |
Combined Attack: IDOR + Plaintext Storage
When the IDOR vulnerability is combined with plaintext storage, attackers can directly extract API tokens from other users' resources:
Attack Chain:
┌─────────────────────────────────────────────────────────────────┐
│ 1. Attacker authenticates with low-privilege account │
│ 2. Uses IDOR to enumerate: /api/dns_credentials/1,2,3... │
│ 3. Reads plaintext API tokens directly from HTTP response │
│ 4. No decryption needed - tokens stored in cleartext │
│ 5. Uses stolen tokens to: │
│ - Modify DNS records (domain hijacking) │
│ - Issue fraudulent SSL certificates │
│ - Pivot to cloud infrastructure │
└─────────────────────────────────────────────────────────────────┘PoC: Extracting Plaintext Credentials via IDOR
# Attacker with low-privilege token accessing admin's DNS credential
curl -H "Authorization: $ATTACKER_TOKEN" \
https://nginx-ui.example.com/api/dns_credentials/1
# Response contains PLAINTEXT API token (no decryption required):
{
"id": 1,
"name": "Production Cloudflare",
"provider": "cloudflare",
"config": {
"credentials": {
"CF_API_TOKEN": "yhyQ7xR...plaintext_token_visible..."
}
}
}Updated CVSS Score with Plaintext Storage
The plaintext storage increases the confidentiality impact:
CVSS 3.1 Score: 8.8 (High)
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Scope Changed (S:C): Impact extends to external services (DNS providers, cloud platforms)
- High Confidentiality (C:H): Plaintext API tokens immediately usable
- High Integrity (I:H): DNS records, certificates can be modified
- High Availability (A:H): Services can be disrupted via DNS/certificate manipulation
---
Attack Scenario: Certificate Hijacking
1. Attacker creates low-privilege account on nginx-ui
2. Uses IDOR to enumerate all DNS credentials: /api/dns_credentials/1,2,3...
3. Steals Cloudflare API token from admin's credential
4. Uses token to:
- Modify DNS records
- Issue fraudulent Let's Encrypt certificates
- Intercept traffic to victim domainsCredit
Discovered by security researcher during authorized security audit.
Recommendation
Immediate Mitigation
- Add User Ownership to Models
// model/model.go
type Model struct {
ID uint64 `gorm:"primary_key" json:"id"`
UserID uint64 `gorm:"index" json:"user_id"` // Add this field
CreatedAt time.Time `json:"created_at"`
UpdatedAt time.Time `json:"updated_at"`
DeletedAt *gorm.DeletedAt `gorm:"index" json:"deleted_at,omitempty"`
}- Filter Queries by Current User
// api/certificate/dns_credential.go
func GetDnsCredential(c *gin.Context) {
id := cast.ToUint64(c.Param("id"))
currentUser := c.MustGet("user").(*model.User)
d := query.DnsCredential
dnsCredential, err := d.Where(
d.ID.Eq(id),
d.UserID.Eq(currentUser.ID), // Add user filter
).First()
if err != nil {
cosy.ErrHandler(c, err)
return
}
// ...
}- Add Authorization Middleware
// middleware/authorization.go
func RequireOwnership(resourceType string) gin.HandlerFunc {
return func(c *gin.Context) {
currentUser := c.MustGet("user").(*model.User)
resourceID := cast.ToUint64(c.Param("id"))
// Check if resource belongs to current user
ownerID, err := getResourceOwner(resourceType, resourceID)
if err != nil || ownerID != currentUser.ID {
c.AbortWithStatusJSON(http.StatusForbidden, gin.H{
"message": "Access denied",
})
return
}
c.Next()
}
}Database Migration
-- Add user_id column to all resource tables
ALTER TABLE dns_credentials ADD COLUMN user_id BIGINT;
ALTER TABLE certs ADD COLUMN user_id BIGINT;
ALTER TABLE acme_users ADD COLUMN user_id BIGINT;
ALTER TABLE sites ADD COLUMN user_id BIGINT;
ALTER TABLE streams ADD COLUMN user_id BIGINT;
ALTER TABLE configs ADD COLUMN user_id BIGINT;
-- Set default owner for existing resources
UPDATE dns_credentials SET user_id = 1 WHERE user_id IS NULL;
UPDATE certs SET user_id = 1 WHERE user_id IS NULL;
-- Add foreign key constraint
ALTER TABLE dns_credentials ADD CONSTRAINT fk_dns_credentials_user
FOREIGN KEY (user_id) REFERENCES users(id);Long-term Improvements
- Implement role-based access control (RBAC)
- Add audit logging for resource access
- Implement resource sharing functionality with explicit permissions
- Add integration tests for authorization checks
---
Remediation for Plaintext Storage
Immediate Fix: Encrypt Sensitive Fields
Apply the same serializer:json[aes] pattern used for S3 credentials to DNS and ACME data:
model/dns_credential.go:
type DnsCredential struct {
Model
Name string `json:"name"`
Config *dns.Config `json:"config,omitempty" gorm:"serializer:json[aes]"` // Add AES encryption
Provider string `json:"provider"`
ProviderCode string `json:"provider_code" gorm:"index"`
}model/acme_user.go:
type AcmeUser struct {
Model
// ...
Key PrivateKey `json:"-" gorm:"serializer:json[aes]"` // Add AES encryption
// ...
}Data Migration
Existing plaintext data must be re-saved to trigger encryption:
func MigrateSensitiveData() error {
// Migrate DNS credentials
var dnsCreds []model.DnsCredential
query.DnsCredential.Find(&dnsCreds)
for _, cred := range dnsCreds {
query.DnsCredential.Save(&cred) // Re-save triggers AES encryption
}
// Migrate ACME users
var acmeUsers []model.AcmeUser
query.AcmeUser.Find(&acmeUsers)
for _, user := range acmeUsers {
query.AcmeUser.Save(&user)
}
return nil
}Summary of Required Changes
| File | Line | Current | Fix |
|---|---|---|---|
model/dns_credential.go | 7 | serializer:json | serializer:json[aes] |
model/acme_user.go | Key field | serializer:json | serializer:json[aes] |
References
- CWE-639: Authorization Bypass Through User-Controlled Key
- OWASP IDOR Prevention Cheat Sheet
- PortSwigger: IDOR Vulnerabilities
Disclosure Timeline
- 2026-03-13: Vulnerability discovered through source code audit
- 2026-03-13: Vulnerability successfully reproduced in local Docker environment
- 2026-03-13: All IDOR operations verified: READ, MODIFY, DELETE
- 2026-03-13: Security advisory prepared
- [Pending]: Report submitted to nginx-ui maintainers
- [Pending]: CVE ID requested
- [Pending]: Patch developed and tested
- [Pending]: Public disclosure (21-90 days after vendor notification)
AnalysisAI
Insecure Direct Object Reference (IDOR) in nginx-ui up to v2.3.3 allows authenticated low-privilege users to access, modify, and delete any resource across all user accounts, including plaintext DNS provider API tokens (Cloudflare, AWS Route53, Alibaba Cloud) and ACME private keys. The application's base Model struct lacks user_id fields, and all resource endpoints query by ID without ownership verification. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Requires authentication to Nginx-UI. … Additional conditions and limiting factors are described in the full assessment. |
| Exploit Scenario | An authenticated attacker directly requests API endpoints with resource IDs belonging to other users (e.g., /api/resource/123), bypassing ownership checks. The application processes the request without verifying user ownership, allowing the attacker to read, modify, or delete arbitrary resources across the multi-user environment. |
Recommended ActionAI
Within 24 hours: inventory all nginx-ui deployments and identify current versions in use; document all connected DNS providers and ACME services. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
More from same product – last 7 days
Unauthenticated remote attackers can invoke MCP tool handlers and exfiltrate the operator's long-lived Meta Graph API ac
Unauthenticated remote code execution in Crawl4AI versions <= 0.8.6 allows attackers to escape the AST-based sandbox in
Privileged GitHub Actions workflow injection in Quest Bot (Discord moderation bot) prior to version 1.0.3 allows remote
Production deployment compromise in Duck Site before 1.0.1 allows remote attackers to push attacker-controlled code as t
Server-side request forgery in Crawl4AI's Docker API server (versions <= 0.8.8) allows unauthenticated remote attackers
Vendor StatusVendor
SUSE
Severity: HighShare
External POC / Exploit Code
Leaving vuln.today
EUVD-2026-17156
GHSA-5hf2-vhj6-gj9m