CVE-2021-3712

Description from NVD

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).

Information Acquisition Date:2021-09-02T14:56Z
CVSS 2.0: 5.8 MEDIUM CVSS 3.x: 7.4 HIGH

▼ CVSS3 Vec CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

▼ CVSS2 Vec AV:N/AC:M/Au:N/C:P/I:N/A:P

NVD References

 https://www.openssl.org/news/secadv/20210824.txt
     source:CONFIRM
     tags:Vendor Advisory    
 https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=94d23fcff9b2a7a8368dfe52214d5c2569882c11
     source:CONFIRM
     tags:Mailing List    Patch    Vendor Advisory    
 https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=ccb0a11145ee72b042d10593a64eaf9e8a55ec12
     source:CONFIRM
     tags:Mailing List    Patch    Vendor Advisory    
 DSA-4963
     source:DEBIAN
     tags:Third Party Advisory    
 [tomcat-dev] 20210825 OpenSSL security announcement - do we need a Tomcat Native release?
     source:MLIST
     tags:Mailing List    Third Party Advisory    
 [oss-security] 20210825 OpenSSL SM2 Decryption Buffer Overflow (CVE-2021-3711), Read buffer overruns processing ASN.1 strings (CVE-2021-3712)
     source:MLIST
     tags:Mailing List    Third Party Advisory    
 [tomcat-dev] 20210826 Re: OpenSSL security announcement - do we need a Tomcat Native release?
     source:MLIST
     tags:Mailing List    Third Party Advisory    
 https://security.netapp.com/advisory/ntap-20210827-0010/
     source:CONFIRM
     tags:Third Party Advisory    

Refer to Information on External Sites

CVE InfomationExploits or more Infomation
mitreEXPLOIT DATABASE
NVD0day.today
vulmon.comgithub
CVE DetailsTwitter
JVN ENG JPN
Reconshell

Software Tag: Linux(6 tweets) OpenSSL(74 tweets) VPN(4 tweets) iOS(1 tweets)



List of frequently cited URLs

URLNum of Times Referred to
https://www.jpcert.or.jp/at/2021/at210036.html24
https://www.openssl.org/news/secadv/20210824.txt7
https://twitter.com/alpinelinux/status/14312399540011868184
https://securityaffairs.co/wordpress/121600/security/synolo...3

▼ Show Information from Twitter(96)


List of frequently cited URLs

URLNum of Times Referred to
www.jpcert.or.jp24
www.openssl.org7
twitter.com4
securityaffairs.co3

▼ Show Information from Twitter(96)


GitHub Search Results: Up to 10
NameURL
No Data

GitHub Search Results: Up to 10
NameURL
No Data

2021/09/14 Score : 1
Added Har-sia Database : 2021/08/24
Last Modified : 2021/09/14
Highest Scored Date : 2021/08/25
Highest Score : 39