{"items":[{"id":"NVI-00017670","kind":"vulnerability","title":"GoFiber Vulnerable to Username Enumeration via Timing Oracle in BasicAuth Default Authorizer","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-g5vh-55hw-rxm8","CVE-2026-44332"],"plain_summary":"GitHub lists this reviewed advisory for github.com/gofiber/fiber/v3. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-40a74e0c0dd07f8f009c5006b22ea772"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-02T13:46:27.000Z","value":"5.3 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-40a74e0c0dd07f8f009c5006b22ea772"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-40a74e0c0dd07f8f009c5006b22ea772","url":"https://github.com/advisories/GHSA-g5vh-55hw-rxm8","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-g5vh-55hw-rxm8","publisher":"GitHub Advisory Database","observed_at":"2026-11-05T03:47:42.887Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-40a74e0c0dd07f8f009c5006b22ea772"],"technology":"github.com/gofiber/fiber/v3","known_exclusions":[],"conditions_summary":"## Summary\n\nThe default `Authorizer` function in GoFiber's BasicAuth middleware uses short-circuit evaluation that skips password hash comparison for non-existent usernames. With bcrypt-hashed passwords (the primary use case), the timing difference between a valid and invalid username is approximately 1,000,000:1 (~100ms vs ~100ns), enabling reliable remote username enumeration.\n\n## Vulnerable Code\n\n**File:** `middleware/basicauth/config.go`, lines 126-138\n\n```go\nif cfg.Authorizer == nil {\n    verifiers := make(map[string]func(string) bool, len(cfg.Users))\n    for u, hpw := range cfg.Users {\n        v, err := parseHashedPassword(hpw)\n        if err != nil {\n            panic(err)\n        }\n        verifiers[u] = v\n    }\n    cfg.Authorizer = func(user, pass string, _ fiber.Ctx) bool {\n        verify, ok := verifiers[user]\n        return ok && verify(pass)   // line 137: short-circuit skips verify() if user unknown\n    }\n}\n```\n\n## Data Flow\n\n1. Attacker sends `Authorization: Basic `\n2. BasicAuth middleware decodes credentials and calls `cfg.Authorizer(user, pass, c)`\n3. Map lookup `verifiers[user]` returns `ok=false` for non-existent users\n4. Go `&&` shor","public_affected_ranges":["<= 3.2.0"]}],"null_published_at":"2026-11-05T19:10:21.448Z","source_updated_at":"2026-07-02T13:46:27.000Z","source_disclosed_at":"2026-07-02T13:46:25.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-05T03:47:42.887Z"}],"next_cursor":null,"snapshot_revision":"42594"}