Nowadays, Bluetooth is an integral part of mobile devices. Smartphones interconnect with smartwatches and wireless headphones. By default, most devices are configured to accept Bluetooth connections from any
nearby unauthenticated device. Bluetooth packets are processed by the Bluetooth chip (also called a controller), and then passed to the host (Android, Linux, etc.). Both, the firmware on the chip and the host Bluetooth subsystem, are a target for Remote Code Execution (RCE) attacks.

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Lately, we came across a remote code execution in a Tomcat web service by utilizing Expression Language. The vulnerable POST body field expected a number. When sending ${1+2} instead, the web site included a Java error message about a failed conversion to java.lang.Long from java.lang.String with value "3".

From that error message we learned a couple of things:

• The application uses Java
• We are able to execute EL expressions
• Output from the EL engine is always returned as String

Whenever you are able to execute code within a Java Context, the most interesting part is to check whether we can get a Runtime object and execute arbitrary OS commands.

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On November 3rd, 2019, we have reported a critical vulnerability affecting the Android Bluetooth subsystem. This vulnerability has been assigned CVE-2020-0022 and was now patched in the latest security patch from February 2020. The security impact is as follows:

• On Android 8.0 to 9.0, a remote attacker within proximity can silently execute arbitrary code with the privileges of the Bluetooth daemon as long as Bluetooth is enabled. No user interaction is required and only the Bluetooth MAC address of the target devices has to be known. For some devices, the Bluetooth MAC address can be deduced from the WiFi MAC address. This vulnerability can lead to theft of personal data and could potentially be used to spread malware (Short-Distance Worm).
• On Android 10, this vulnerability is not exploitable for technical reasons and only results in a crash of the Bluetooth daemon.
• Android versions even older than 8.0 might also be affected but we have not evaluated the impact.

Users are strongly advised to install the latest available security patch from February 2020. If you have no patch available yet or your device is not supported anymore, you can try to mitigate the impact by some generic behavior rules:

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Recently, I discovered a sandbox breakout in the Groovy Sandbox used by the Jenkins script-security Plugin in their Pipeline Plugin for build scripts. We responsibly disclosed this vulnerability and in the current version of Jenkins it has been fixed and the according Jenkins Security Advisory 2019-09-12 has been published. In this blogpost I want to report a bit on the technical details of the vulnerability.

Description

The groovy sandbox transforms some AST nodes of the script to add security checks. For example

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During security assessments we sometimes obtain access to a restricted shell on a target system. To advance further and gain complete control of the system, the next step is usually to break out of this shell. If the restricted shell provides access to certain system binaries, these binaries can often be exploited to perform such a break out. Here we would like to show an interesting example of such a break out by using the tcpdump binary.

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Dear all,

innovaphone fixed several vulnerabilities in two VoIP products that we disclosed a while ago. The affected products are the Linux Application Platform and the IPVA. Unfortunately, the release notes are not public (yet?) and the vendor does not include information about the vulnerabilities for the Linux Application Platform. Therefore, we decided to publish some more technical details for the issues.

Multiple Vulnerabilities in Linux Application Platform

The Linux Application Platform was affected by three vulnerabilities that could be chained to get full root access to a target system. However, the initial access vector is only exploitable by authenticated users. The vulnerabilities have been identified on the Linux Application Platform V10 SR41. According to the vendor they have been fixed in V10 SR57.

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Again, Cisco released security advisories for their software-defined networking (SDN) solution called Application Centric Infrastructure (ACI). As before (see blog post here), the published advisories originated from research performed in our ACI lab.

The following advisories have been published:

Cisco Nexus 9000 Series Fabric Switches ACI Mode Fabric Infrastructure VLAN Unauthorized Access Vulnerability
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-n9kaci-bypass
CVSS Base Score: 7.4

Cisco Application Policy Infrastructure Controller REST API Privilege Escalation Vulnerability
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190703-ccapic-restapi
CVSS Base Score: 7.2

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During code reviews we often see developers using weak RNGs like math.random() to generate cryptographic secrets. We think it is commonly known that weak random number generators (RNG) must not be used for any kind of secret and recommend using secure alternatives. I explicitly did not state a specific language yet, because basically every language offers both weak and strong RNGs.

So I asked myself: What if I use a weak RNG to generate a secret? Is it possible to recover the secret from some derived value, like a hash?

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It is possible to spoof the URLs that Plume will open to arbitrary locations because of how Plume parses URLs. The preview of an URL in a tweet will show the complete (at least the host name and the first few chars of the URL) but shortened URL. However, if the URL contains a semicolon (;) the URL that will be opened is the part after the semicolon.

An attacker can make use of this behavior by specifying a URL like the following in a Tweet or direct message:

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Lately, I’ve experienced some weird Pidgin crashes when I was copy&pasting into chat windows. The strange part was: I didn’t even know what triggered the crash because I actually didn’t know what was in my clipboard at this exact point. This is a quick write-up of how I investigated the issue and some interesting properties I found out about clipboards.

Everything started with a document that I was editing in a Windows VM in Microsoft Word. At some point, I wanted to copy some lines of the document and paste it into a Pidgin chat window on my Linux host system. As I did this, I noticed that when I pasted the data into the chat window it included a lot of white spaces. I thought something went wrong and just tried to delete it by pressing CTRL+A (to mark everything) and press BACKSPACE. But this caused Pidgin (2.13.0-5 on Arch Linux) to close with a segfault and created a core dump.

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