IBM AIX: openssl_advisory38 (CVE-2022-4450): Vulnerability in openssl affects AIX

IBM AIX: openssl_advisory38 (CVE-2022-4450): Vulnerability in openssl affects AIX

Severity

8

CVSS

(AV:N/AC:L/Au:N/C:N/I:N/A:C)

Published

02/08/2023

Created

07/27/2023

Added

07/27/2023

Modified

01/30/2025

Description

The function PEM_read_bio_ex() reads a PEM file from a BIO and parses and decodes the "name" (e.g. "CERTIFICATE"), any header data and the payload data. If the function succeeds then the "name_out", "header" and "data" arguments are populated with pointers to buffers containing the relevant decoded data. The caller is responsible for freeing those buffers. It is possible to construct a PEM file that results in 0 bytes of payload data. In this case PEM_read_bio_ex() will return a failure code but will populate the header argument with a pointer to a buffer that has already been freed. If the caller also frees this buffer then a double free will occur. This will most likely lead to a crash. This could be exploited by an attacker who has the ability to supply malicious PEM files for parsing to achieve a denial of service attack. The functions PEM_read_bio() and PEM_read() are simple wrappers around PEM_read_bio_ex() and therefore these functions are also directly affected. These functions are also called indirectly by a number of other OpenSSL functions including PEM_X509_INFO_read_bio_ex() and SSL_CTX_use_serverinfo_file() which are also vulnerable. Some OpenSSL internal uses of these functions are not vulnerable because the caller does not free the header argument if PEM_read_bio_ex() returns a failure code. These locations include the PEM_read_bio_TYPE() functions as well as the decoders introduced in OpenSSL 3.0. The OpenSSL asn1parse command line application is also impacted by this issue.

Solution(s)

• ibm-aix-openssl_advisory38

References

• https://attackerkb.com/topics/cve-2022-4450
• CVE - 2022-4450
• https://aix.software.ibm.com/aix/efixes/security/openssl_advisory38.asc