Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Vulnerabilities

OpenSSL Patch for Low Severity Issue Creates Critical Flaw

A fix included in the OpenSSL updates released last week introduced a critical vulnerability that could potentially lead to arbitrary code execution, the OpenSSL Project warned on Monday.

A fix included in the OpenSSL updates released last week introduced a critical vulnerability that could potentially lead to arbitrary code execution, the OpenSSL Project warned on Monday.

OpenSSL versions 1.1.0a, 1.0.2i and 1.0.1u were released on September 22 to address more than a dozen security holes. One of the issues affecting OpenSSL 1.1.0 is a low severity denial-of-service (DoS) bug related to excessive allocation of memory in the tls_get_message_header() function.

The flaw, reported by Shi Lei of Qihoo 360 and identified as CVE-2016-6307, is considered “low severity” because it can only be exploited if certain conditions are met.

The OpenSSL Project rolled out a fix in version 1.1.0a, but Google Security Engineer Robert Swiecki soon discovered that the patch created a critical use-after-free vulnerability related to large message sizes.

“The patch applied to address CVE-2016-6307 resulted in an issue where if a message larger than approx 16k is received then the underlying buffer to store the incoming message is reallocated and moved. Unfortunately a dangling pointer to the old location is left which results in an attempt to write to the previously freed location,” the OpenSSL Project wrote in its advisory.

The critical flaw (CVE-2016-6309) can result in a crash, but it could also lead to arbitrary code execution. The problem has been addressed with the release of OpenSSL 1.1.0b.

OpenSSL developers also announced on Monday the release of version 1.0.2j, which patches a missing CRL sanity check issue affecting only version 1.0.2i (CVE-2016-7052).

The OpenSSL Project hopes that by quickly releasing a patch for the critical vulnerability, users will update their installations directly to the newest versions instead of the ones made available last week.

Advertisement. Scroll to continue reading.

The most serious weakness fixed last week is CVE-2016-6304, which can be exploited for DoS attacks by sending an excessively large OCSP Status Request extension to the targeted server. Another interesting issue fixed last week, albeit a low severity one, is Sweet32, a recently disclosed attack method that can be leveraged to recover potentially sensitive data from a large volume of encrypted traffic.

Related Reading: Encrypted Network Traffic Comes at a Cost

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.

Learn how the LOtL threat landscape has evolved, why traditional endpoint hardening methods fall short, and how adaptive, user-aware approaches can reduce risk.

Watch Now

Join the summit to explore critical threats to public cloud infrastructure, APIs, and identity systems through discussions, case studies, and insights into emerging technologies like AI and LLMs.

Register

People on the Move

Robert Shaker II has joined application security firm ActiveState as Chief Product and Technology Officer.

MorganFranklin Cyber has promoted Nick Stallone and Ferdinand Hamada into newly created roles.

Jessica Newman has joined Sophos as General Manager of Global Cyber Insurance.

More People On The Move

Expert Insights

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest cybersecurity news, threats, and expert insights. Unsubscribe at any time.