摘要:
A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.
安全等级: Low
公告ID: KylinSec-SA-2025-2305
发布日期: 2025年4月20日
关联CVE: CVE-2023-39326
一个恶意的HTTP发送方可以利用分块扩展(chunk extensions)技术,导致接收方在读取请求或响应主体时,从网络读取比实际主体内容多得多的字节数据。恶意HTTP客户端可进一步利用此漏洞,当服务器处理器未能完整读取请求主体时,强制服务器自动读取大量数据(最高可达约1GiB)。
技术背景:
分块扩展是HTTP协议中较少使用的功能特性,允许在使用分块传输编码时在请求/响应主体中包含额外元数据。标准库net/http的分块编码读取器会直接丢弃这些元数据。攻击者可借机在每个传输字节中插入大量元数据段进行利用。
安全修复:
当前分块读取器已增加校验机制,当实际主体与编码字节的比例过低时,将直接返回错误。
cve名称 | 产品 | 组件 | 是否受影响 |
---|---|---|---|
CVE-2023-39326 | KY3.4-5A | skopeo | Unaffected |
CVE-2023-39326 | V6 | skopeo | Unaffected |