Update your Android devices now! Google patches two actively exploited vulnerabilities

Google has patched 53 vulnerabilities in its Android October security updates, two of which are known to be actively exploited. Google’s security bulletin notes that there are indications that these two vulnerabilities may be under limited, targeted exploitation.

If your Android phone is at patch level 2023-10-06 or later then the two issues discussed below have been fixed. The updates have been made available for Android 11, 12, 12L and 13. Android partners are notified of all issues at least a month before publication, however, this doesn’t always mean that the patches are available for devices from all vendors.

The Cybersecurity & Infrastructure Security Agency (CISA) has already added these two actively exploited vulnerabilities to its catalog of known to be exploited vulnerabilities. This means that Federal Civilian Executive Branch (FCEB) agencies need to remediate these vulnerabilities before a given due date. CVE-2023-4863 was due on October 4, 2023 and CVE-2023-4211 has to be patched by October 24, 2023. 

You can find your device’s Android version number, security update level, and Google Play system level in your Settings app. You’ll get notifications when updates are available for you, but you can also manually check for updates.

For most phones it works like this: Under About phone or About device you can tap on Software updates to check if there are new updates available for your device, although there may be slight differences based on the brand, type, and Android version of your device.

The Common Vulnerabilities and Exposures (CVE) database lists publicly disclosed computer security flaws. The CVEs listed as actively exploited are:

CVE-2023-4863: a heap buffer overflow in libwebp which affects many applications that use this library to encode and decode images in the WebP format, allowed a remote attacker to perform an out of bounds memory write via a crafted HTML page.

This is a vulnerability that impacts many applications, which we have discussed at length in our article explaining how it was used to install spyware. The vulnerability is patched if your phone is at patch level 2023-10-05.

But the next one isn’t. Your phone needs to be at patch level 2023-10-06 for that.

CVE-2023-4211: a local non-privileged user can make improper GPU memory processing operations to gain access to already freed memory. This vulnerability affects multiple versions of Arm Mali GPU drivers which are used in a broad range of Android device models, including on Android phones developed by Google, Samsung, Huawei, and Xiaomi, as well as in some Linux devices. A GPU is a specific type of chip mostly used for graphics-related tasks, such as rendering images and videos, but also for resource-heavy calculations, such as training artificial intelligence and crypto-mining.

Normally Google uses two different patch levels for each round of updates, so Android partners have the flexibility to fix a subset of vulnerabilities that are similar across all Android devices more quickly. The higher the patch level number, the more vulnerabilities will be fixed. In this round the only difference between patch levels 2023-10-05 and 2023-10-06 is the important patch for CVE-2023-4211. 

In its own October security bulletin, chip manufacturer Qualcomm said that there are indications from Google Threat Analysis Group and Google Project Zero that CVE-2023-33106CVE-2023-33107CVE-2022-22071, and CVE-2023-33063 may be under limited, targeted exploitation. It is unclear when patches for these issues will be included in security updates by the respective vendors.

Let’s hope that all these patches reach our devices soon.

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Pieter Arntz

Malware Intelligence Researcher

Was a Microsoft MVP in consumer security for 12 years running. Can speak four languages. Smells of rich mahogany and leather-bound books.