Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Vulnerabilities

Non-Security OpenSSL Bugs Lead to Serious Vulnerability

The OpenSSL Project released on Tuesday versions 1.0.2h and 1.0.1t to patch several vulnerabilities that can be exploited for denial-of-service (DoS) attacks, arbitrary code execution and traffic decryption.

The OpenSSL Project released on Tuesday versions 1.0.2h and 1.0.1t to patch several vulnerabilities that can be exploited for denial-of-service (DoS) attacks, arbitrary code execution and traffic decryption.

The latest versions of OpenSSL address a high severity flaw (CVE-2016-2107) that was introduced in 2013 as part of the fix for the Lucky 13 TLS attack. The vulnerability, reported on April 13 by Juraj Somorovsky, allows a man-in-the-middle (MitM) attacker to decrypt traffic when the connection uses an AES CBC cipher and the server supports AES-NI instructions.

OpenSSL 1.0.2h and 1.0.1t also patch three low severity issues related to the incorrect handling of large amounts of input data by the EVP_EncodeUpdate() and EVP_EncryptUpdate() functions, and incorrect handling of memory when ASN.1 data is read from a BIO. These flaws have been assigned the CVE identifiers CVE-2016-2105, CVE-2016-2106 and CVE-2016-2109.

The OpenSSL Project also informed users of a high severity vulnerability (CVE-2016-2108) that is a combination of two non-security bugs.

One of them, reported in April 2015 by Huzaifa Sidhpurwala of Red Hat and independently by Hanno Böck, is related to the mishandling of negative zero integers. The bug was patched in June 2015, without anyone being aware of its security impact.

The second bug, related to the mishandling of large universal tags, was reported on March 1, 2016. David Benjamin of Google revealed on March 31 that the two bugs result in a potentially exploitable memory corruption vulnerability. An attacker can exploit the flaw to cause OpenSSL to crash and possibly even to execute arbitrary code.

Here is the OpenSSL Project’s technical description of CVE-2016-2108:

“In previous versions of OpenSSL, ASN.1 encoding the value zero represented as a negative integer can cause a buffer underflow with an out-of-bounds write in i2c_ASN1_INTEGER. The ASN.1 parser does not normally create ‘negative zeroes’ when parsing ASN.1 input, and therefore, an attacker cannot trigger this bug.

 

Advertisement. Scroll to continue reading.

However, a second, independent bug revealed that the ASN.1 parser (specifically, d2i_ASN1_TYPE) can misinterpret a large universal tag as a negative zero value. Large universal tags are not present in any common ASN.1 structures (such as X509) but are accepted as part of ANY structures.

 

Therefore, if an application deserializes untrusted ASN.1 structures containing an ANY field, and later reserializes them, an attacker may be able to trigger an out-of-bounds write. This has been shown to cause memory corruption that is potentially exploitable with some malloc implementations.”

Since the first bug was patched in June 2015 with the release of OpenSSL 1.0.2c and 1.0.1o, the attack method discovered by Google’s David Benjamin does not work against these or more recent versions.

Written By

Eduard Kovacs (@EduardKovacs) is a managing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Understand how to go beyond effectively communicating new security strategies and recommendations.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Vulnerabilities

Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Breaches

OpenAI has confirmed a ChatGPT data breach on the same day a security firm reported seeing the use of a component affected by an...

IoT Security

A group of seven security researchers have discovered numerous vulnerabilities in vehicles from 16 car makers, including bugs that allowed them to control car...

Vulnerabilities

A researcher at IOActive discovered that home security systems from SimpliSafe are plagued by a vulnerability that allows tech savvy burglars to remotely disable...

Risk Management

The supply chain threat is directly linked to attack surface management, but the supply chain must be known and understood before it can be...

Cybercrime

Patch Tuesday: Microsoft calls attention to a series of zero-day remote code execution attacks hitting its Office productivity suite.

Vulnerabilities

Patch Tuesday: Microsoft warns vulnerability (CVE-2023-23397) could lead to exploitation before an email is viewed in the Preview Pane.

Vulnerabilities

The latest Chrome update brings patches for eight vulnerabilities, including seven reported by external researchers.