Ubuntu Security Notice 2914-1 - Yuval Yarom, Daniel Genkin, and Nadia Heninger discovered that OpenSSL was vulnerable to a side-channel attack on modular exponentiation. On certain CPUs, a local attacker could possibly use this issue to recover RSA keys. This flaw is known as CacheBleed. Adam Langley discovered that OpenSSL incorrectly handled memory when parsing DSA private keys. A remote attacker could use this issue to cause OpenSSL to crash, resulting in a denial of service, or possibly execute arbitrary code. Various other issues were also addressed.
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Ubuntu Security Notice USN-2914-1
March 01, 2016
openssl vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 15.10
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS
Summary:
Several security issues were fixed in OpenSSL.
Software Description:
- openssl: Secure Socket Layer (SSL) cryptographic library and tools
Details:
Yuval Yarom, Daniel Genkin, and Nadia Heninger discovered that OpenSSL was
vulnerable to a side-channel attack on modular exponentiation. On certain
CPUs, a local attacker could possibly use this issue to recover RSA keys.
This flaw is known as CacheBleed. (CVE-2016-0702)
Adam Langley discovered that OpenSSL incorrectly handled memory when
parsing DSA private keys. A remote attacker could use this issue to cause
OpenSSL to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2016-0705)
Guido Vranken discovered that OpenSSL incorrectly handled hex digit
calculation in the BN_hex2bn function. A remote attacker could use this
issue to cause OpenSSL to crash, resulting in a denial of service, or
possibly execute arbitrary code. (CVE-2016-0797)
Emilia Käsper discovered that OpenSSL incorrectly handled memory when
performing SRP user database lookups. A remote attacker could possibly use
this issue to cause OpenSSL to consume memory, resulting in a denial of
service. (CVE-2016-0798)
Guido Vranken discovered that OpenSSL incorrectly handled memory when
printing very long strings. A remote attacker could use this issue to cause
OpenSSL to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2016-0799)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 15.10:
libssl1.0.0 1.0.2d-0ubuntu1.4
Ubuntu 14.04 LTS:
libssl1.0.0 1.0.1f-1ubuntu2.18
Ubuntu 12.04 LTS:
libssl1.0.0 1.0.1-4ubuntu5.35
After a standard system update you need to reboot your computer to make
all the necessary changes.
References:
http://www.ubuntu.com/usn/usn-2914-1
CVE-2016-0702, CVE-2016-0705, CVE-2016-0797, CVE-2016-0798,
CVE-2016-0799
Package Information:
https://launchpad.net/ubuntu/+source/openssl/1.0.2d-0ubuntu1.4
https://launchpad.net/ubuntu/+source/openssl/1.0.1f-1ubuntu2.18
https://launchpad.net/ubuntu/+source/openssl/1.0.1-4ubuntu5.35