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OpenAdvisories
High ALAS2023-2026-2053 2 CVEs

Important: freerdp security update (Amazon Linux 2023)

Published Aug 17, 2026 · Updated Aug 17, 2026

Summary

Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-64621: FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp_file_apply_to_settings() (client/common/file.c) when parsing the selectedmonitors field of a .rdp connection file. The MonitorIds array is allocated through the settings object, and a raw non-owning pointer to it is freed on the strtoul error path without clearing settings->MonitorIds, leaving it dangling; at teardown freerdp_settings_free() frees the same buffer again. An attacker who convinces a victim to open a crafted .rdp file with oversized monitor tokens can trigger a size-controlled double-free in any FreeRDP CLI client (xfreerdp/sdl-freerdp/wlfreerdp) in the default configuration. CVE-2026-64620: 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.

Fixed packages 11

ReleasePackageFixed in
Amazon Linux · 2023 freerdp 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 freerdp-debuginfo 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 freerdp-debugsource 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 freerdp-devel 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 freerdp-libs 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 freerdp-libs-debuginfo 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 freerdp-server 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 freerdp-server-debuginfo 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 libwinpr 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 libwinpr-debuginfo 2:3.6.3-1.amzn2023.0.14
Amazon Linux · 2023 libwinpr-devel 2:3.6.3-1.amzn2023.0.14

Vulnerabilities 2

  • Critical 9.8

    FreeRDP before 3.28.0 Heap Buffer Overflow via crypto_rsa_common

    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 check…

  • High 7.3

    FreeRDP before 3.28.0 Double-Free via selectedmonitors

    FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp_file_apply_to_settings() (client/common/file.c) when parsing the selectedmonitors field of a .rdp connection file. The MonitorIds array is allocated…

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-64620.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-64621.html