Threaticon
Toggle sidebar

You're viewing a limited, public preview. Log in for full access.

Log in User Guide
Log in Get started
Vulnerabilities CVE-2026-64620

CVE-2026-64620

Critical
Open
TLP:CLEAR

FreeRDP before 3.28.0 Heap Buffer Overflow via crypto_rsa_common

AI Analysis

No AI analysis yet.

Description

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.

Details

CVSS Score
9.3
EPSS Score
0.85%

55.2th percentile

CVSS Vector
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
Confidence
90%
Published
Jul 20, 2026
Last Modified
Jul 20, 2026
No notes yet. Click "Add Note" to create the first analysis note.
No opinions yet. Be the first to assess this intelligence.
Leaving Threaticon

This link opens an external site that isn't part of the platform.