Symfony XML 实体扩展安全漏洞

CVE编号

N/A

利用情况

暂无

补丁情况

N/A

披露时间

2024-05-30

漏洞描述

Symfony 2.0.11 carried a [similar] XXE security fix, however, on review of ZF2 I also noted a vulnerability to XML Entity Expansion (XEE) attacks whereby all extensions making use of libxml2 have no defense against XEE Quadratic Blowup Attacks. The vulnerability is a function of there being no current method of disabling custom entities in PHP (i.e. defined internal to the XML document without using external entities). In a QBA, a long entity can be defined and then referred to multiple times in document elements, creating a memory sink with which Denial Of Service attacks against a host's RAM can be mounted. The use of the LIBXML_NOENT or equivalent option in a dependent extension amplified the impact (it doesn't actually mean "No Entities"). In addition, libxml2's innate defense against the related Exponential or Billion Laugh's XEE attacks is active only so long as the LIBXML_PARSEHUGE is NOT set (it disables libxml2's hardcoded entity recursion limit). No instances of these two options were noted, but it's worth referencing for the future.

解决建议

建议您更新当前系统或软件至最新版，完成漏洞的修复。

参考链接
https://github.com/advisories/GHSA-c636-cg5r-2498

CVSS3评分 N/A

• 攻击路径 N/A
• 攻击复杂度 N/A
• 权限要求 N/A
• 影响范围 N/A
• 用户交互 N/A
• 可用性 N/A
• 保密性 N/A
• 完整性 N/A

N/A

CWE-ID	漏洞类型
CWE-611	XML外部实体引用的不恰当限制（XXE）

Exp相关链接

- avd.aliyun.com