ALAS2-2018-1102

Related Vulnerabilities: CVE-2017-3735   CVE-2018-0495   CVE-2018-0732   CVE-2018-0739  

During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack.(CVE-2018-0732) Libgcrypt before 1.7.10 and 1.8.x before 1.8.3 allows a memory-cache side-channel attack on ECDSA signatures that can be mitigated through the use of blinding during the signing process in the _gcry_ecc_ecdsa_sign function in cipher/ecc-ecdsa.c, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.(CVE-2018-0495) Constructed ASN.1 types with a recursive definition (such as can be found in PKCS7) could eventually exceed the stack given malicious input with excessive recursion. This could result in a Denial Of Service attack. There are no such structures used within SSL/TLS that come from untrusted sources so this is considered safe.(CVE-2018-0739) While parsing an IPAddressFamily extension in an X.509 certificate, it is possible to do a one-byte overread. This would result in an incorrect text display of the certificate. This bug has been present since 2006.(CVE-2017-3735)

ALAS2-2018-1102


Amazon Linux 2 Security Advisory: ALAS-2018-1102
Advisory Release Date: 2018-11-07 22:07 Pacific
Advisory Updated Date: 2018-11-08 23:41 Pacific
Severity: Medium

Issue Overview:

During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack.(CVE-2018-0732)

Libgcrypt before 1.7.10 and 1.8.x before 1.8.3 allows a memory-cache side-channel attack on ECDSA signatures that can be mitigated through the use of blinding during the signing process in the _gcry_ecc_ecdsa_sign function in cipher/ecc-ecdsa.c, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.(CVE-2018-0495)

Constructed ASN.1 types with a recursive definition (such as can be found in PKCS7) could eventually exceed the stack given malicious input with excessive recursion. This could result in a Denial Of Service attack. There are no such structures used within SSL/TLS that come from untrusted sources so this is considered safe.(CVE-2018-0739)

While parsing an IPAddressFamily extension in an X.509 certificate, it is possible to do a one-byte overread. This would result in an incorrect text display of the certificate. This bug has been present since 2006.(CVE-2017-3735)


Affected Packages:

openssl


Issue Correction:
Run yum update openssl to update your system.

New Packages:
i686:
    openssl-1.0.2k-16.amzn2.0.1.i686
    openssl-libs-1.0.2k-16.amzn2.0.1.i686
    openssl-devel-1.0.2k-16.amzn2.0.1.i686
    openssl-static-1.0.2k-16.amzn2.0.1.i686
    openssl-perl-1.0.2k-16.amzn2.0.1.i686
    openssl-debuginfo-1.0.2k-16.amzn2.0.1.i686

src:
    openssl-1.0.2k-16.amzn2.0.1.src

x86_64:
    openssl-1.0.2k-16.amzn2.0.1.x86_64
    openssl-libs-1.0.2k-16.amzn2.0.1.x86_64
    openssl-devel-1.0.2k-16.amzn2.0.1.x86_64
    openssl-static-1.0.2k-16.amzn2.0.1.x86_64
    openssl-perl-1.0.2k-16.amzn2.0.1.x86_64
    openssl-debuginfo-1.0.2k-16.amzn2.0.1.x86_64