Code Aurora ACDB Audio Driver: memory corruption flaw under attack

What is affected

Code Aurora ACDB Audio Driver is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.

The Code Aurora audio calibration database (acdb) audio driver contains a stack-based buffer overflow vulnerability that allows for privilege escalation. Code Aurora is used in third-party products such as Qualcomm and Android.

What an attacker can do

This is a memory corruption flaw. It lets an attacker corrupt the program's memory by feeding it specially crafted content: a web page, a file or a network message. The result ranges from a crash to the attacker running their own code.

How it is reached

Needs access to the device or a file opened on it

Access the attacker needs

No account needed

Does the victim have to do something?

No, works without the victim doing anything

What to do

1. At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
2. If you administer Code Aurora ACDB Audio Driver at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
3. If the product is past its support date and no fix exists, take it off the internet or retire it.

Apply updates per vendor instructions.

Vendor advisories and fixes

• web.archive.orgweb.archive.org/web/20161226013354/https:/www.codeaurora.org/news/security-advisories/stac

How urgent is it

CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on September 15, 2022, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by October 6, 2022, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.

The EPSS model estimates a 1.5% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 74% of all scored vulnerabilities.

Its CVSS severity score is 8.4 out of 10 (high), as recorded in the US National Vulnerability Database.

Technical description

Stack-based buffer overflow in the acdb_ioctl function in audio_acdb.c in the acdb audio driver for the Linux kernel 2.6.x and 3.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, allows attackers to gain privileges via an application that leverages /dev/msm_acdb access and provides a large size value in an ioctl argument.