Description
The public API function BIO_new_NDEF is a helper function used for streaming
ASN.1 data via a BIO. It is primarily used internally to OpenSSL to support the
SMIME, CMS and PKCS7 streaming capabilities, but may also be called directly by
end user applications.
The function receives a BIO from the caller, prepends a new BIO_f_asn1 filter
BIO onto the front of it to form a BIO chain, and then returns the new head of
the BIO chain to the caller. Under certain conditions, for example if a CMS
recipient public key is invalid, the new filter BIO is freed and the function
returns a NULL result indicating a failure. However, in this case, the BIO chain
is not properly cleaned up and the BIO passed by the caller still retains
internal pointers to the previously freed filter BIO. If the caller then goes on
to call BIO_pop() on the BIO then a use-after-free will occur. This will most
likely result in a crash.
This scenario occurs directly in the internal function B64_write_ASN1() which
may cause BIO_new_NDEF() to be called and will subsequently call BIO_pop() on
the BIO. This internal function is in turn called by the public API functions
PEM_write_bio_ASN1_stream, PEM_write_bio_CMS_stream, PEM_write_bio_PKCS7_stream,
SMIME_write_ASN1, SMIME_write_CMS and SMIME_write_PKCS7.
Other public API functions that may be impacted by this include
i2d_ASN1_bio_stream, BIO_new_CMS, BIO_new_PKCS7, i2d_CMS_bio_stream and
i2d_PKCS7_bio_stream.
The OpenSSL cms and smime command line applications are similarly affected.
Understanding This Vulnerability
This Common Vulnerabilities and Exposures (CVE) entry provides detailed information about a security vulnerability that has been publicly disclosed. CVEs are standardized identifiers assigned by MITRE Corporation to track and catalog security vulnerabilities across software and hardware products.
The severity rating (UNKNOWN) indicates the potential impact of this vulnerability based on the CVSS (Common Vulnerability Scoring System) framework. Higher severity ratings typically indicate vulnerabilities that could lead to more significant security breaches if exploited. Security teams should prioritize remediation efforts based on severity, exploit availability, and the EPSS (Exploit Prediction Scoring System) score, which predicts the likelihood of exploitation in the wild.
If this vulnerability affects products or systems in your infrastructure, we recommend reviewing the affected products section, checking for available patches or updates from vendors, and implementing recommended workarounds or solutions until a permanent fix is available. Organizations should also monitor security advisories and threat intelligence feeds for updates about active exploitation of this vulnerability.