Mbed TLS before 2.28.10 and 3.x before 3.6.3, in some cases of failed memory allocation or hardware errors, uses uninitialized stack memory to compose the TLS Finished message, potentially leading to authentication bypasses such as replays.

The remote Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8123-1 advisory.

    It was discovered that Mbed TLS incorrectly handled memory allocation failures. A remote attacker could     possibly use this issue to crash the program. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04     LTS. (CVE-2021-44732)

    Jonathan Winzig discovered that Mbed TLS incorrectly handled crafted inputs. A remote attacker could     possibly use this issue to crash the program, resulting in a denial of service. This issue only affected     Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS. (CVE-2024-23775)

    It was discovered that Mbed TLS incorrectly handled the TLS handshake. A remote attacker could possibly     use this issue to break the security guarantees of the TLS handshake. (CVE-2025-27810)

    Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly documented the behavior of a function.
    Application code relying on the documented behavior might be affected. A remote attacker could possibly     use this issue to execute arbitrary code. (CVE-2025-47917)

    Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled crafted input. A remote attacker     could possibly use this issue to crash the program, resulting in a denial of service. (CVE-2025-48965)

    It was discovered that Mbed TLS incorrectly handled a race condition. An attacker could possibly use this     issue to extract AES keys. (CVE-2025-52496)

    Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled certain invalid input. A remote     attacker could possibly use this issue to crash the program, resulting in a denial of service.
    (CVE-2025-52497)

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

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

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2025:0337 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2025-27810:
    Mbed TLS before 2.28.10 and 3.x before 3.6.3, in some cases of failed memory allocation or hardware     errors, uses uninitialized stack memory to compose the TLS Finished message, potentially leading to     authentication bypasses such as replays.

    CVE-2025-27809:
    Mbed TLS before 2.28.10 and 3.x before 3.6.3, on the client side, accepts servers that have trusted     certificates for arbitrary hostnames unless the TLS client application calls mbedtls_ssl_set_hostname.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

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

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Mbed TLS before 2.28.10 and 3.x before 3.6.3, in some cases of failed memory allocation or hardware     errors, uses uninitialized stack memory to compose the TLS Finished message, potentially leading to     authentication bypasses such as replays. (CVE-2025-27810)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
304014	Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS : Mbed TLS vulnerabilities (USN-8123-1)	Nessus	Ubuntu Local Security Checks	critical
276298	TencentOS Server 4: mbedtls (TSSA-2025:0337)	Nessus	Tencent Local Security Checks	medium
248825	Linux Distros Unpatched Vulnerability : CVE-2025-27810	Nessus	Misc.	medium

Detections

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CVE-2025-27810

medium

Tenable Plugins

critical

medium

medium