OpenSSL up to 1.0.2y/1.1.1k ASN.1 out-of-bounds

Summaryinfo

A vulnerability identified as problematic has been detected in OpenSSL up to 1.0.2y/1.1.1k. This vulnerability affects the function d2i/X509_get1_email/X509_REQ_get1_email/X509_get1_ocsp of the component ASN.1 Handler. This manipulation causes out-of-bounds. This vulnerability appears as CVE-2021-3712. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenSSL up to 1.0.2y/1.1.1k (Network Encryption Software). It has been declared as problematic. Affected by this vulnerability is the function d2i/X509_get1_email/X509_REQ_get1_email/X509_get1_ocsp of the component ASN.1 Handler. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. The summary by CVE is:

ASN.1 strings are represented internally within OpenSSL as an ASN1_STRING structure which contains a buffer holding the string data and a field holding the buffer length. This contrasts with normal C strings which are repesented as a buffer for the string data which is terminated with a NUL (0) byte. Although not a strict requirement, ASN.1 strings that are parsed using OpenSSL's own "d2i" functions (and other similar parsing functions) as well as any string whose value has been set with the ASN1_STRING_set() function will additionally NUL terminate the byte array in the ASN1_STRING structure. However, it is possible for applications to directly construct valid ASN1_STRING structures which do not NUL terminate the byte array by directly setting the "data" and "length" fields in the ASN1_STRING array. This can also happen by using the ASN1_STRING_set0() function. Numerous OpenSSL functions that print ASN.1 data have been found to assume that the ASN1_STRING byte array will be NUL terminated, even though this is not guaranteed for strings that have been directly constructed. Where an application requests an ASN.1 structure to be printed, and where that ASN.1 structure contains ASN1_STRINGs that have been directly constructed by the application without NUL terminating the "data" field, then a read buffer overrun can occur. The same thing can also occur during name constraints processing of certificates (for example if a certificate has been directly constructed by the application instead of loading it via the OpenSSL parsing functions, and the certificate contains non NUL terminated ASN1_STRING structures). It can also occur in the X509_get1_email(), X509_REQ_get1_email() and X509_get1_ocsp() functions. If a malicious actor can cause an application to directly construct an ASN1_STRING and then process it through one of the affected OpenSSL functions then this issue could be hit. This might result in a crash (causing a Denial of Service attack). It could also result in the disclosure of private memory contents (such as private keys, or sensitive plaintext). Fixed in OpenSSL 1.1.1l (Affected 1.1.1-1.1.1k). Fixed in OpenSSL 1.0.2za (Affected 1.0.2-1.0.2y).

The weakness was presented 08/24/2021 as 20210824.txt. The advisory is shared at openssl.org. This vulnerability is known as CVE-2021-3712. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 211827 (Oracle Linux 9 : edk2 (ELSA-2024-12842)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.1.1j or 1.0.2za eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.openssl.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (211827). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Network Encryption Software

Name

• OpenSSL

Version

• 1.0.2a
• 1.0.2b
• 1.0.2c
• 1.0.2d
• 1.0.2e
• 1.0.2f
• 1.0.2g
• 1.0.2h
• 1.0.2i
• 1.0.2j
• 1.0.2k
• 1.0.2l
• 1.0.2m
• 1.0.2n
• 1.0.2o
• 1.0.2p
• 1.0.2q
• 1.0.2r
• 1.0.2s
• 1.0.2t
• 1.0.2u
• 1.0.2v
• 1.0.2w
• 1.0.2x
• 1.0.2y
• 1.1.1
• 1.1.1a
• 1.1.1b
• 1.1.1c
• 1.1.1d
• 1.1.1e
• 1.1.1f
• 1.1.1g
• 1.1.1h
• 1.1.1i
• 1.1.1j
• 1.1.1k

License

• open-source

Website

• Product: https://www.openssl.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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