Medium: openssl11

Issue Overview:

A security vulnerability has been identified in all supported versions of OpenSSL related to the verification of X.509 certificate chains that include policy constraints. Attackers may be able to exploit this vulnerability by creating a malicious certificate chain that triggers exponential use of computational resources, leading to a denial-of-service (DoS) attack on affected systems. Policy processing is disabled by default but can be enabled by passing the -policy' argument to the command line utilities or by calling the X509_VERIFY_PARAM_set1_policies()’ function. (CVE-2023-0464)

Applications that use a non-default option when verifying certificates may be vulnerable to an attack from a malicious CA to circumvent certain checks. Invalid certificate policies in leaf certificates are silently ignored by OpenSSL and other certificate policy checks are skipped for that certificate. A malicious CA could use this to deliberately assert invalid certificate policies in order to circumvent policy checking on the certificate altogether. Policy processing is disabled by default but can be enabled by passing the -policy' argument to the command line utilities or by calling the X509_VERIFY_PARAM_set1_policies()’ function. (CVE-2023-0465)

The function X509_VERIFY_PARAM_add0_policy() is documented to implicitly enable the certificate policy check when doing certificate verification. However the implementation of the function does not enable the check which allows certificates with invalid or incorrect policies to pass the certificate verification. As suddenly enabling the policy check could break existing deployments it was decided to keep the existing behavior of the X509_VERIFY_PARAM_add0_policy() function. Instead the applications that require OpenSSL to perform certificate policy check need to use X509_VERIFY_PARAM_set1_policies() or explicitly enable the policy check by calling X509_VERIFY_PARAM_set_flags() with the X509_V_FLAG_POLICY_CHECK flag argument. Certificate policy checks are disabled by default in OpenSSL and are not commonly used by applications. (CVE-2023-0466)

Affected Packages:

openssl11

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update openssl11 to update your system.

New Packages:

aarch64:  
    openssl11-1.1.1g-12.amzn2.0.14.aarch64  
    openssl11-libs-1.1.1g-12.amzn2.0.14.aarch64  
    openssl11-devel-1.1.1g-12.amzn2.0.14.aarch64  
    openssl11-static-1.1.1g-12.amzn2.0.14.aarch64  
    openssl11-debuginfo-1.1.1g-12.amzn2.0.14.aarch64  
  
i686:  
    openssl11-1.1.1g-12.amzn2.0.14.i686  
    openssl11-libs-1.1.1g-12.amzn2.0.14.i686  
    openssl11-devel-1.1.1g-12.amzn2.0.14.i686  
    openssl11-static-1.1.1g-12.amzn2.0.14.i686  
    openssl11-debuginfo-1.1.1g-12.amzn2.0.14.i686  
  
src:  
    openssl11-1.1.1g-12.amzn2.0.14.src  
  
x86_64:  
    openssl11-1.1.1g-12.amzn2.0.14.x86_64  
    openssl11-libs-1.1.1g-12.amzn2.0.14.x86_64  
    openssl11-devel-1.1.1g-12.amzn2.0.14.x86_64  
    openssl11-static-1.1.1g-12.amzn2.0.14.x86_64  
    openssl11-debuginfo-1.1.1g-12.amzn2.0.14.x86_64  

Additional References

Red Hat: CVE-2023-0464, CVE-2023-0465, CVE-2023-0466

Mitre: CVE-2023-0464, CVE-2023-0465, CVE-2023-0466