Google has released its fifth security update for its Android mobile operating system so far in 2016, this time patching 40 vulnerabilities. Of those, 12 are rated as critical, with two of the critical issues identified as remote code execution vulnerabilities in Android's much maligned mediaserver component.
In addition to the two critical issues in mediaserver, there are five other vulnerabilities in mediaserver that Google has rated as having high impact and two as having moderate impact. Google's mediaserver, which is in the same general area of Android as the libstagefright (Stagefright) media library, has been the subject of security researcher scrutiny since July 2015 when Zimperium zLabs Vice President of Platform Research and Exploitation Joshua Drake first reported flaws.
The two critical flaws in mediaserver—CVE-2016-2428 and CVE-2016-2429—were reported to Google by Alibaba security researcher Weichao Sun.
"During media file and data processing of a specially crafted file, a vulnerability in mediaserver could allow an attacker to cause memory corruption and remote code execution as the mediaserver process," Google warns in its advisory. "This issue is rated as Critical severity due to the possibility of remote code execution within the context of the mediaserver service."
Also of note is a critical issue (CVE-2015-1805) that Google is only now patching in Android that was first patched by the upstream Linux kernel community in June 2015.
"An elevation of privilege vulnerability in the kernel could enable a local malicious application to execute arbitrary code within the context of the kernel," Google's advisory states.
For the five issues (CVE-2016-2448, CVE-2016-2449, CVE-2016-2450, CVE-2016-2451 and CVE-2016-2452) in mediaserver that Google rates as having high impact, the root vulnerability is privilege escalation. The privilege escalation issues were reported to Google by security researchers Mingjian Zhou, Chiachih Wu and Xuxian Jiang from research firm Core Team.
"An elevation of privilege vulnerability in mediaserver could enable a local malicious application to execute arbitrary code within the context of an elevated system application," Google's advisory warns.
The moderate flaws in mediaserver are identified as CVE-2016-2459 and CVE-2016-2460 and were reported to Google by Trend Micro security researcher Peter Pi. The flaws are information disclosure issues that could potentially enable an application to gain unauthorized access to sensitive information.
Zuk Avraham, founder and CTO of Zimperium, isn't surprised that Google continues to find vulnerabilities in Android month after month.
"Google is getting better and better at closing more holes, but there are just so many out there," he told eWEEK. "In every release, we see new remote code execution vulnerabilities as well as local privilege escalation."
Avraham's company was the first to report on issues related to Android's mediaserver, which Google has patched nearly every month since first starting a monthly patch cycle in August 2015.
"Unfortunately, it does not look like we'll have a month or quarter without new mediaserver bugs anytime soon," he said.
Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.