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