Buffer Overflow The advisory has been revoked - it doesn't affect any version of package Mbed-TLS/mbedtls  (opens in a new tab)


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  • Snyk IDSNYK-UNMANAGED-MBEDTLSMBEDTLS-5950353
  • published8 Oct 2023
  • disclosed7 Oct 2023
  • creditUnknown

Introduced: 7 Oct 2023

CVE-2023-43615  (opens in a new tab)
CWE-120  (opens in a new tab)

How to fix?

Upgrade Mbed-TLS/mbedtls to version 2.28.5, 3.5.0 or higher.

Amendment

This was deemed not a vulnerability.

Overview

Affected versions of this package are vulnerable to Buffer Overflow in processing certain data, an attacker can cause a buffer overflow by sending specially crafted input.

Workaround

The vulnerability is not present in the default build of Mbed TLS. It is only present if the compile-time configuration enables the vulnerable cipher suites. If you use a custom configuration and you want to check that the vulnerable cipher suites are not included in your build:

  1. In Mbed TLS 3.x or 2.28, make sure that MBEDTLS_CIPHER_NULL_CIPHER is not enabled.

  2. In Mbed TLS 2.28, also make sure that MBEDTLS_REMOVE_ARC4_CIPHERSUITES is enabled, or that MBEDTLS_ARC4_C is not enabled.

If the vulnerable cipher suites are enabled at compile time, they can be disabled at run time by calling mbedtls_ssl_conf_ciphersuites() with a list that does not include null-cipher or RC4 cipher suites. Alternatively, call mbedtls_ssl_conf_ciphersuites_for_version() for all affected protocol versions (SSLv3, TLS 1.0, TLS 1.1, TLS 1.2).

Note:

Applications that only accept TLS 1.3 are not affected.

The vulnerability only affects data records after a successful handshake, so if your TLS endpoint requires authentication, it can only be exploited by an authenticated client. Also, a firewall that prevents the negotiation of null-cipher or RC4 cipher suites will prevent the vulnerability from being exploited by traffic that goes through the firewall.

References