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Amazon Linux 2023 : freerdp, freerdp-devel, freerdp-libs (ALAS2023-2026-3435)

high Nessus Plugin ID 379818

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-3435 advisory.

 FreeRDP 3.0.0 before 3.32.2 server-side RDP peer input parsing skips the six-byte body of a slow-path input event with an unknown message type without checking it lies within the packet's declared length, causing a WinPR stream assertion failure. A remote RDP client with an active session can send a truncated unknown input event to abort assertion-enabled server processes, causing denial of service.
 (CVE-2026-121951)

 FreeRDP before 3.32.2 contains a use-after-free vulnerability in Emulate_SCardReleaseContext that frees the emulated SCardContext before its worker thread is cancelled and joined. A malicious server can send ESTABLISHCONTEXT, a long-timeout GETSTATUSCHANGE, then RELEASECONTEXT smartcard IRPs to corrupt heap memory or crash clients using smartcard emulation. (CVE-2026-121955)

 FreeRDP before 3.32.2 contains a double free in the WinPR Kerberos SSPI retrieveSomeTgt function, which installs the krb5 default realm into a target principal that has an empty realm without taking ownership of it. Unauthenticated remote clients can send a crafted NLA/CredSSP u2u TGT request whose server-name component contains '@' to corrupt the heap and crash the server process. (CVE-2026-121956)

 FreeRDP before 3.32.2 contains a use-after-free vulnerability that allows malicious RDP servers to corrupt client memory by racing the RDPGFX ResetGraphics handler against the planar bitmap decoder. Attackers can send ResetGraphics while concurrently sending compressed bitmaps of 32 bpp or more to trigger heap use- after-free or out-of-bounds read/write on shared planar buffers. (CVE-2026-121957)

 FreeRDP through 3.32.1 has a heap out-of-bounds write in the RDPGFX client because the delete_surface callback truncates surface hash keys to 16 bits, leaving the surface table inconsistent so HashTable_GetKeys writes past its allocated key array. A malicious or man-in-the-middle RDP server can exploit this by creating surfaceId 0xFFFF, closing the RDPGFX channel, sending repeated DELETESURFACE PDUs, and then sending ENDFRAME or RESETGRAPHICS. (CVE-2026-121958)

 FreeRDP before 3.32.2 contains a denial of service vulnerability in the NLA-enabled shadow server when a CredSSP TSRequest omits negoTokens. Unauthenticated attackers can send a crafted seven-byte TSRequest containing only the version field to trigger a fatal WINPR_ASSERT and abort the server process.
 (CVE-2026-121960)

 FreeRDP before 3.32.2 contains a heap buffer overflow in transport_default_read_pdu when handling partial Early User Authorization reads during PROTOCOL_HYBRID_EX CredSSP. A malicious RDP server can split the four-byte EUA result into short reads that advance the stream pointer beyond the 16 KiB allocation, causing an out-of-bounds write and client denial of service. (CVE-2026-121962)

 FreeRDP before 3.32.2 contains a heap-based buffer overflow in the RD Gateway RPC client, where rpc_client_recv_fragment writes BIND_ACK and ALTER_CONTEXT_RESP fragments into a persistent PDU stream after checking only total capacity rather than remaining capacity from the current stream position. A malicious or compromised RD Gateway can send crafted RPC fragments with manipulated alloc_hint and frag_length values to overwrite client heap memory with attacker-controlled data, causing a crash or potentially arbitrary code execution. (CVE-2026-121964)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'dnf update freerdp --releasever 2023.12.20261112' or or 'dnf update --advisory ALAS2023-2026-3435 --releasever 2023.12.20261112' to update your system.

See Also

https://alas.aws.amazon.com//AL2023/ALAS2023-2026-3435.html

https://alas.aws.amazon.com/faqs.html

https://explore.alas.aws.amazon.com/CVE-2026-121951.html

https://explore.alas.aws.amazon.com/CVE-2026-121955.html

https://explore.alas.aws.amazon.com/CVE-2026-121956.html

https://explore.alas.aws.amazon.com/CVE-2026-121957.html

https://explore.alas.aws.amazon.com/CVE-2026-121958.html

https://explore.alas.aws.amazon.com/CVE-2026-121960.html

https://explore.alas.aws.amazon.com/CVE-2026-121962.html

https://explore.alas.aws.amazon.com/CVE-2026-121964.html

Plugin Details

Severity: High

ID: 379818

File Name: al2023_ALAS2023-2026-3435.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 11/12/2026

Updated: 11/12/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.53

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-121958

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 7.7

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2026-121964

Vulnerability Information

CPE: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:freerdp-debuginfo, p-cpe:/a:amazon:linux:freerdp-debugsource, p-cpe:/a:amazon:linux:freerdp-devel, p-cpe:/a:amazon:linux:freerdp-libs-debuginfo, p-cpe:/a:amazon:linux:freerdp-libs, p-cpe:/a:amazon:linux:freerdp-server-debuginfo, p-cpe:/a:amazon:linux:freerdp-server, p-cpe:/a:amazon:linux:freerdp, p-cpe:/a:amazon:linux:libwinpr-debuginfo, p-cpe:/a:amazon:linux:libwinpr-devel, p-cpe:/a:amazon:linux:libwinpr

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 11/12/2026

Vulnerability Publication Date: 11/4/2026

Reference Information

CVE: CVE-2026-121951, CVE-2026-121955, CVE-2026-121956, CVE-2026-121957, CVE-2026-121958, CVE-2026-121960, CVE-2026-121962, CVE-2026-121964