Vulnerability CVE-2019-1543


Published: 2019-03-06

Description:
ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input for every encryption operation. RFC 7539 specifies that the nonce value (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce length and front pads the nonce with 0 bytes if it is less than 12 bytes. However it also incorrectly allows a nonce to be set of up to 16 bytes. In this case only the last 12 bytes are significant and any additional leading bytes are ignored. It is a requirement of using this cipher that nonce values are unique. Messages encrypted using a reused nonce value are susceptible to serious confidentiality and integrity attacks. If an application changes the default nonce length to be longer than 12 bytes and then makes a change to the leading bytes of the nonce expecting the new value to be a new unique nonce then such an application could inadvertently encrypt messages with a reused nonce. Additionally the ignored bytes in a long nonce are not covered by the integrity guarantee of this cipher. Any application that relies on the integrity of these ignored leading bytes of a long nonce may be further affected. Any OpenSSL internal use of this cipher, including in SSL/TLS, is safe because no such use sets such a long nonce value. However user applications that use this cipher directly and set a non-default nonce length to be longer than 12 bytes may be vulnerable. OpenSSL versions 1.1.1 and 1.1.0 are affected by this issue. Due to the limited scope of affected deployments this has been assessed as low severity and therefore we are not creating new releases at this time. Fixed in OpenSSL 1.1.1c (Affected 1.1.1-1.1.1b). Fixed in OpenSSL 1.1.0k (Affected 1.1.0-1.1.0j).

Type:

CWE-310

(Cryptographic Issues)

Vendor: Openssl
Product: Openssl 
Version:
1.1.1b
1.1.1a
1.1.1
1.1.0j
1.1.0i
1.1.0h
1.1.0g
1.1.0f
1.1.0e
1.1.0d
1.1.0c
1.1.0b
1.1.0a
1.1.0

CVSS2 => (AV:N/AC:M/Au:N/C:P/I:P/A:N)

CVSS Base Score
Impact Subscore
Exploitability Subscore
5.8/10
4.9/10
8.6/10
Exploit range
Attack complexity
Authentication
Remote
Medium
No required
Confidentiality impact
Integrity impact
Availability impact
Partial
Partial
None

 References:
https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=ee22257b1418438ebaf54df98af4e24f494d1809
https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=f426625b6ae9a7831010750490a5f0ad689c5ba3
https://www.openssl.org/news/secadv/20190306.txt

Related CVE
CVE-2019-1552
OpenSSL has internal defaults for a directory tree where it can find a configuration file as well as certificates used for verification in TLS. This directory is most commonly referred to as OPENSSLDIR, and is configurable with the --prefix / --opens...
CVE-2019-1559
If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid...
CVE-2019-0190
A bug exists in the way mod_ssl handled client renegotiations. A remote attacker could send a carefully crafted request that would cause mod_ssl to enter a loop leading to a denial of service. This bug can be only triggered with Apache HTTP Server ve...
CVE-2018-5407
Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attacks via a side-channel timing attack on 'port contention'.
CVE-2018-0734
The OpenSSL DSA signature algorithm has been shown to be vulnerable to a timing side channel attack. An attacker could use variations in the signing algorithm to recover the private key. Fixed in OpenSSL 1.1.1a (Affected 1.1.1). Fixed in OpenSSL 1.1....
CVE-2018-0735
The OpenSSL ECDSA signature algorithm has been shown to be vulnerable to a timing side channel attack. An attacker could use variations in the signing algorithm to recover the private key. Fixed in OpenSSL 1.1.0j (Affected 1.1.0-1.1.0i). Fixed in Ope...
CVE-2016-7056
A timing attack flaw was found in OpenSSL 1.0.1u and before that could allow a malicious user with local access to recover ECDSA P-256 private keys.
CVE-2018-12438
The Elliptic Curve Cryptography library (aka sunec or libsunec) allows a memory-cache side-channel attack on ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the loc...

Copyright 2019, cxsecurity.com

 

Back to Top