🔴 严重 | CVE-2026-64620 — FreeRDP before 3.28.0 (affected <=3.27.1) contains...
🔴 《严重安全漏洞：CVE-2026-64620》
CVSS 评分: 严重（9.3） 状态: Received 发布时间: 2026-07-20
漏洞描述
FreeRDP before 3.28.0 (affected <=3.27.1) contains a heap-based buffer overflow in crypto_rsa_common() (libfreerdp/crypto/crypto.c). The function writes the modular-exponentiation result into the caller's output buffer via BN_bn2bin() and only afterward checks output_length > out_length, so out-of-bounds bytes are written before the bounds check. On the server side, when a client selects RDP Standard Security, the encrypted client random is decrypted into a fixed 32-byte buffer. Because the server publishes its RSA public key, an unauthenticated attacker can forge a ciphertext whose decrypted value is up to the full modulus length (e.g. 256 bytes for RSA-2048), overflowing the 32-byte heap buffer by up to ~224 attacker-controlled bytes pre-authentication, resulting in denial of service.
🔍 技术细节
| 字段 | 值 |
|---|---|
| CVE ID | CVE-2026-64620 |
| CVSS 评分 | 9.3 🔴 |
| 严重程度 | 严重 |
| CVSS 向量 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| CWE 分类 | CWE-122 |
| 发布时间 | 2026-07-20 |
| 最后更新 | 2026-07-20 |
| 状态 | Received |
| 数据来源 | disclosure@vulncheck.com |