CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
Percentile
52.1%
A double-free vulnerability was found in OpenSSLβs PEM_read_bio_ex function. The function PEM_read_bio_ex() reads a PEM file from a BIO and parses and decodes the βnameβ (for example, βCERTIFICATEβ), any header data, and the payload data. If the function succeeds, then the βname_out,β βheader,β and βdataβ arguments are populated with pointers to buffers containing the relevant decoded data. The caller is responsible for freeing those buffers. Constructing a PEM file that results in 0 bytes of payload data is possible. In this case, PEM_read_bio_ex() will return a failure code but will populate the header argument with a pointer to a freed buffer. A double-free will occur if the caller also frees this buffer. This will most likely lead to a crash. This could be exploited by an attacker who can supply malicious PEM files for parsing to achieve a denial of service attack.