--- title: "Prevent user enumeration using Guard or the new Authenticator-based Security" system_id: "symfony" category: "frameworks" advisory_mode: "core" published_date: "2021-05-13T20:23:02Z" updated_date: "2026-03-13T22:16:14.858636Z" severity: "low" exploit_status: "unknown" source_confidence: "official" verification_status: "triage-manual" verification_mode: "synthetic" artifact_mode: "synthetic" last_run_id: "" target_types: - "lab-local" - "lab-public" - "authorized-third-party" allow_public_validation: "yes, with ownership or explicit authorization" authorization_prerequisite: "asset ownership proof or explicit written authorization" minimal_validation: "read-only probe, controlled payload, reversible test" aliases: - "BIT-symfony-2021-21424" - "CVE-2021-21424" - "GHSA-5pv8-ppvj-4h68" affected_versions: - "v2.8.0" - "v2.8.1" - "v2.8.10" - "v2.8.11" - "v2.8.12" - "v2.8.13" - "v2.8.14" - "v2.8.15" - "v2.8.16" - "v2.8.17" - "v2.8.18" - "v2.8.19" - "v2.8.2" - "v2.8.20" - "v2.8.21" - "v2.8.22" - "v2.8.23" - "v2.8.24" - "v2.8.25" - "v2.8.26" fixed_versions: - "5.2.8" - "3.4.48" - "4.4.23" - "2.10.7" - "2.11.3" - "1.29.2" - "1.31.1" - "3.4.49" - "4.4.24" - "5.2.9" secure_code_topics: - "xss-output-encoding" - "authz-server-side-recheck" - "path-traversal-guard" primary_source: "https://github.com/symfony/symfony/security/advisories/GHSA-5pv8-ppvj-4h68" --- # Prevent user enumeration using Guard or the new Authenticator-based Security ## 本地实证状态 - 实证状态: `triage-manual` - 实证方式: `synthetic` - Artifact 模式: `synthetic` - 最近运行: `-` - 浏览器证据: `missing` - Run Bundle: `-` ## 事件层 - Canonical ID: `symfony--CVE-2021-21424` - 系统: `symfony` - 严重度: `low` - 来源置信度: `official` - 官方主源: https://github.com/symfony/symfony/security/advisories/GHSA-5pv8-ppvj-4h68 - 影响版本: `v2.8.0, v2.8.1, v2.8.10, v2.8.11, v2.8.12, v2.8.13, v2.8.14, v2.8.15, v2.8.16, v2.8.17` - 修复版本: `5.2.8, 3.4.48, 4.4.23, 2.10.7, 2.11.3, 1.29.2, 1.31.1, 3.4.49, 4.4.24, 5.2.9` ## 其他来源 - https://nvd.nist.gov/vuln/detail/CVE-2021-21424 - https://github.com/symfony/symfony/commit/2a581d22cc621b33d5464ed65c4bc2057f72f011 - https://symfony.com/cve-2021-21424 - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VRUS2H2SSOQWNLBD35SKIWIDQEMV2PD3 - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UC7BND775DVZDQT3RMGD2HVB2PKLJDJW - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RH7TMM5CHQYBFFGXWRPJDPB3SKCZXI2M - https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KENRNLB3FYXYGDWRBH2PDBOZZKOD7VY4 - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VRUS2H2SSOQWNLBD35SKIWIDQEMV2PD3 - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UC7BND775DVZDQT3RMGD2HVB2PKLJDJW - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RH7TMM5CHQYBFFGXWRPJDPB3SKCZXI2M - https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KENRNLB3FYXYGDWRBH2PDBOZZKOD7VY4 - https://lists.debian.org/debian-lts-announce/2023/07/msg00014.html - https://github.com/symfony/symfony - https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2021-21424.yaml - https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security/CVE-2021-21424.yaml - https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2021-21424.yaml - https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-guard/CVE-2021-21424.yaml - https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/maker-bundle/CVE-2021-21424.yaml - https://github.com/FriendsOfPHP/security-advisories/blob/master/lexik/jwt-authentication-bundle/CVE-2021-21424.yaml ## 实验层 - 仅用于自有资产、测试环境或已明确授权目标。 - 允许公网可达目标，但必须满足资产归属或明确授权前提。 - 最小化验证方式: 最小化验证、只读探测、可审计回显、受控注入。 - 若该案例涉及插件、模块或扩展，应同时检查供应链与升级策略。 - 禁止场景: 无归属证明或无明确授权的公网目标；知名公共网站或与测试无关的第三方资产；会造成持久破坏、数据越权下载或不可回滚影响的动作 ## 修复示例 - [javascript-typescript:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/javascript-typescript/xss-output-encoding.md) - [nodejs:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/nodejs/xss-output-encoding.md) - [java:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/java/xss-output-encoding.md) - [php:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/php/xss-output-encoding.md) - [python:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/python/xss-output-encoding.md) - [ruby:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/ruby/xss-output-encoding.md) - [csharp:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/csharp/xss-output-encoding.md) - [go:xss-output-encoding](/Users/x/websafe/05-defense/secure-code/go/xss-output-encoding.md) - [javascript-typescript:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/javascript-typescript/authz-server-side-recheck.md) - [nodejs:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/nodejs/authz-server-side-recheck.md) - [java:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/java/authz-server-side-recheck.md) - [php:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/php/authz-server-side-recheck.md) - [python:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/python/authz-server-side-recheck.md) - [ruby:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/ruby/authz-server-side-recheck.md) - [csharp:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/csharp/authz-server-side-recheck.md) - [go:authz-server-side-recheck](/Users/x/websafe/05-defense/secure-code/go/authz-server-side-recheck.md) - [javascript-typescript:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/javascript-typescript/path-traversal-guard.md) - [nodejs:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/nodejs/path-traversal-guard.md) - [java:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/java/path-traversal-guard.md) - [php:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/php/path-traversal-guard.md) - [python:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/python/path-traversal-guard.md) - [ruby:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/ruby/path-traversal-guard.md) - [csharp:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/csharp/path-traversal-guard.md) - [go:path-traversal-guard](/Users/x/websafe/05-defense/secure-code/go/path-traversal-guard.md)