SAML_SIGNATURE_WRAPPING security protocol_error ai_generated true

SAML XML 签名包装攻击：攻击者注入绕过签名验证的恶意断言

SAML XML signature wrapping attack: attacker injects malicious assertions that bypass signature validation

ID: security/saml-xml-signature-wrapping-bypass

其他格式: JSON · Markdown 中文 · English
85%修复率
87%置信度
1证据数
2023-08-20首次发现

版本兼容性

版本状态引入弃用备注
OpenSAML 4.3.0 active — — —
Shibboleth IdP 4.3.0 active — — —
SimpleSAMLphp 1.19.0 active — — —
Microsoft AD FS 2019 active — — —
Okta SAML 1.0.0 active — — —

根因分析

SAML 响应解析器验证原始断言的签名，但处理通过 XML 包装（例如使用 ID 重复或 SOAP 信封操作）注入的未签名断言，从而允许攻击者控制的属性。

English

SAML response parser validates the signature on the original assertion but processes a different, unsigned assertion injected via XML wrapping (e.g., using ID duplication or SOAP envelope manipulation), allowing attacker-controlled attributes.

generic

官方文档

https://docs.oasis-open.org/security/saml/v2.0/saml-core-2.0-os.pdf

解决方案

  1. Enforce strict assertion ID uniqueness and reject responses with duplicate IDs. Example in Java using OpenSAML: set `strictValidation=true` and configure `IdAttributeResolver` to check for duplicates.
  2. Use a whitelist of allowed assertion IDs or require that the signed assertion is the only one processed, ignoring any wrapped content.

无效尝试

常见但无效的做法:

  1. 85% 失败

    Attackers can place the malicious assertion before the signed one; parser may process the first unsigned assertion.

  2. 75% 失败

    Wrapping attacks use well-formed XML that passes schema validation; the attack is structural, not syntactic.

  3. 80% 失败

    Attackers can sign the malicious assertion with a stolen or self-signed certificate if the trust store is misconfigured.