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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
| Attack Vector | NETWORK |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | NONE |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | NONE |
| Integrity Impact | NONE |
| Availability Impact | HIGH |
| Source | Type | Description |
|---|---|---|
| [email protected] | Primary |
en
CWE-415
|
| 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary |
en
CWE-415
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| openssl | openssl | * | <built-in method update of dict object at 0x72a963c69080> | Application |
| openssl | openssl | * | <built-in method update of dict object at 0x72a9cd08d840> | Application |
| stormshield | stormshield_network_security | * | <built-in method update of dict object at 0x72a963c6bbc0> | Application |
| stormshield | stormshield_network_security | * | <built-in method update of dict object at 0x72a963c682c0> | Application |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:a:stormshield:stormshield_network_security:*:*:*:*:*:*:*:* |