Double Free Affecting edk2-ovmf package, versions <0:20200801stable-1.amzn2.0.5


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.18% (55th percentile)

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  • Snyk IDSNYK-AMZN2-EDK2OVMF-6457836
  • published19 Mar 2024
  • disclosed8 Feb 2023

Introduced: 8 Feb 2023

CVE-2022-4450  (opens in a new tab)
CWE-415  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2 edk2-ovmf to version 0:20200801stable-1.amzn2.0.5 or higher.
This issue was patched in ALAS2-2024-2502.

NVD Description

Note: Versions mentioned in the description apply only to the upstream edk2-ovmf package and not the edk2-ovmf package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 relevant fixed versions and status.

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.

CVSS Scores

version 3.1