CVE-2026-64620

Kaynağa göre önem derecesi

Trivy'nin kendi etiketi CRITICAL. Kritik diyenler: NVD. Daha düşük diyenler: Red Hat (yüksek), AlmaLinux (yüksek), Amazon (yüksek), Oracle (yüksek), Rocky Linux (yüksek), Ubuntu (orta).

Açıklama

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.

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Referanslar

• https://access.redhat.com/errata/RHSA-2026:54486
• https://access.redhat.com/security/cve/CVE-2026-64620
• https://bugzilla.redhat.com/2502752
• https://bugzilla.redhat.com/2502766
• https://bugzilla.redhat.com/2503096
• https://bugzilla.redhat.com/2509985
• https://bugzilla.redhat.com/2510004
• https://bugzilla.redhat.com/2510125