A Lucky 13 timing side channel in mbedtls_ssl_decrypt_buf in library/ssl_msg.c in Trusted Firmware Mbed TLS through 2.23.0 allows an attacker to recover secret key information. This affects CBC mode because of a computed time difference based on a padding length.

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

  - A Lucky 13 timing side channel in mbedtls_ssl_decrypt_buf in library/ssl_msg.c in Trusted Firmware Mbed     TLS through 2.23.0 allows an attacker to recover secret key information. This affects CBC mode because of     a computed time difference based on a padding length. (CVE-2020-16150)

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

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - A Lucky 13 timing side channel in mbedtls_ssl_decrypt_buf in library/ssl_msg.c in Trusted Firmware Mbed
    TLS through 2.23.0 allows an attacker to recover secret key information. This affects CBC mode because of
    a computed time difference based on a padding length. (CVE-2020-16150)

The remote host is affected by the vulnerability described in GLSA-202301-08 (Mbed TLS: Multiple Vulnerabilities)

  - A Lucky 13 timing side channel in mbedtls_ssl_decrypt_buf in library/ssl_msg.c in Trusted Firmware Mbed     TLS through 2.23.0 allows an attacker to recover secret key information. This affects CBC mode because of     a computed time difference based on a padding length. (CVE-2020-16150)

  - An issue was discovered in Arm Mbed TLS before 2.23.0. Because of a side channel in modular     exponentiation, an RSA private key used in a secure enclave could be disclosed. (CVE-2020-36421)

  - An issue was discovered in Arm Mbed TLS before 2.23.0. A side channel allows recovery of an ECC private     key, related to mbedtls_ecp_check_pub_priv, mbedtls_pk_parse_key, mbedtls_pk_parse_keyfile,     mbedtls_ecp_mul, and mbedtls_ecp_mul_restartable. (CVE-2020-36422)

  - An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a     certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
    (CVE-2020-36423)

  - An issue was discovered in Arm Mbed TLS before 2.24.0. An attacker can recover a private key (for RSA or     static Diffie-Hellman) via a side-channel attack against generation of base blinding/unblinding values.
    (CVE-2020-36424)

  - An issue was discovered in Arm Mbed TLS before 2.24.0. It incorrectly uses a revocationDate check when     deciding whether to honor certificate revocation via a CRL. In some situations, an attacker can exploit     this by changing the local clock. (CVE-2020-36425)

  - An issue was discovered in Arm Mbed TLS before 2.24.0. mbedtls_x509_crl_parse_der has a buffer over-read     (of one byte). (CVE-2020-36426)

  - An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The     calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters     could lead to denial of service when generating Diffie-Hellman key pairs. (CVE-2020-36475)

  - An issue was discovered in Mbed TLS before 2.24.0 (and before 2.16.8 LTS and before 2.7.17 LTS). There is     missing zeroization of plaintext buffers in mbedtls_ssl_read to erase unused application data from memory.
    (CVE-2020-36476)

  - An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching     the expected common name (the cn argument of mbedtls_x509_crt_verify) with the actual certificate name is     mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that     extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain     by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to     control that IP address, though). (CVE-2020-36477)

  - An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL     algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is     considered valid. However, if the parameters do not match in any way, then the certificate should be     considered invalid. (CVE-2020-36478)

  - A Denial of Service vulnerability exists in mbed TLS 3.0.0 and earlier in the mbedtls_pkcs12_derivation     function when an input password's length is 0. (CVE-2021-43666)

  - Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an     mbedtls_ssl_set_session() failure. (CVE-2021-44732)

  - In Mbed TLS before 2.28.0 and 3.x before 3.1.0, psa_cipher_generate_iv and psa_cipher_encrypt allow policy     bypass or oracle-based decryption when the output buffer is at memory locations accessible to an untrusted     application. (CVE-2021-45450)

  - An issue was discovered in Mbed TLS before 2.28.1 and 3.x before 3.2.0. In some configurations, an     unauthenticated attacker can send an invalid ClientHello message to a DTLS server that causes a heap-based     buffer over-read of up to 255 bytes. This can cause a server crash or possibly information disclosure     based on error responses. Affected configurations have MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE enabled and     MBEDTLS_SSL_IN_CONTENT_LEN less than a threshold that depends on the configuration: 258 bytes if using     mbedtls_ssl_cookie_check, and possibly up to 571 bytes with a custom cookie check function.
    (CVE-2022-35409)

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

The remote Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3249 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-3249-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                      Markus Koschany     December 26, 2022                             https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : mbedtls     Version        : 2.16.9-0~deb10u1     CVE ID         : CVE-2019-16910 CVE-2019-18222 CVE-2020-10932 CVE-2020-10941                      CVE-2020-16150 CVE-2020-36421 CVE-2020-36422 CVE-2020-36423                      CVE-2020-36424 CVE-2020-36425 CVE-2020-36426 CVE-2020-36475                      CVE-2020-36476 CVE-2020-36478 CVE-2021-24119 CVE-2021-43666                      CVE-2021-44732 CVE-2022-35409     Debian Bug     : 941265 963159 972806 1002631

    Multiple security vulnerabilities have been discovered in mbedtls, a     lightweight crypto and SSL/TLS library, which may allow attackers to obtain     sensitive information like the RSA private key or cause a denial of service     (application or server crash).

    For Debian 10 buster, these problems have been fixed in version     2.16.9-0~deb10u1.

    We recommend that you upgrade your mbedtls packages.

    For the detailed security status of mbedtls please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/mbedtls

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: This is a digitally signed message part

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

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

- Update to 2.16.8

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Manuel Pegourie-Gonnard reports :

When decrypting/authenticating (D)TLS record in a connection using a CBC ciphersuite without the Encrypt-then-Mac extension RFC 7366, Mbed TLS used dummy rounds of the compression function associated with the hash used for HMAC in order to hide the length of the padding to remote attackers, as recommended in the original Lucky Thirteen paper.

A local attacker who is able to observe the state of the cache could monitor the presence of mbedtls_md_process() in the cache in order to determine when the actual computation ends and when the dummy rounds start. This is a reliable target as it's always called at least once, in response to a previous attack. The attacker can then continue with one of many well-documented Lucky 13 variants.

ID	Name	Product	Family	Type	Severity
243350	Linux Distros Unpatched Vulnerability : CVE-2020-16150	Nessus	Misc.	Local	medium
426901	Alpine: multiple mbedtls2 packages: security update to 2.16.8-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	medium
426901	Alpine: multiple mbedtls2 packages: security update to 2.16.8-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	medium
424182	Alpine: multiple mbedtls packages: security update to 2.16.8-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	medium
424182	Alpine: multiple mbedtls packages: security update to 2.16.8-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	medium
169842	GLSA-202301-08 : Mbed TLS: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	Local	critical
169300	Debian dla-3249 : libmbedcrypto3 - security update	Nessus	Debian Local Security Checks	Local	critical
140762	Fedora 32 : mbedtls (2020-8b0d59bac6)	Nessus	Fedora Local Security Checks	Local	medium
140621	Fedora 31 : mbedtls (2020-48a1ae610c)	Nessus	Fedora Local Security Checks	Local	medium
140312	FreeBSD : Mbed TLS -- Local side channel attack on classical CBC decryption in (D)TLS (4c69240f-f02c-11ea-838a-0011d823eebd)	Nessus	FreeBSD Local Security Checks	Local	medium

Detections

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CVE-2020-16150

medium

Tenable Plugins

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medium

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critical

critical

medium

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medium