Google Android on Qualcomm ce_util_to_unsigned_bin memory corruption

Summaryinfo

A vulnerability was found in Google Android on Qualcomm. It has been classified as critical. The impacted element is the function ce_util_to_unsigned_bin. The manipulation leads to memory corruption. This vulnerability is uniquely identified as CVE-2015-9138. The attack is possible to be carried out remotely. No exploit exists. To fix this issue, it is recommended to deploy a patch.

Detailsinfo

A vulnerability was found in Google Android on Qualcomm (Smartphone Operating System) (unknown version). It has been rated as critical. This issue affects the function ce_util_to_unsigned_bin. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Automobile, Snapdragon Mobile, Snapdragon Wear, and Small Cell SoC FSM9055, IPQ4019, MDM9206, MDM9607, MDM9625, MDM9635M, MDM9640, MDM9645, MDM9650, MDM9655, MSM8909W, SD 210/SD 212/SD 205, SD 400, SD 410/12, SD 425, SD 430, SD 450, SD 600, SD 615/16/SD 415, SD 617, SD 625, SD 650/52, SD 800, SD 808, SD 810, SD 820, SD 820A, SD 835, SD 845, SD 850, and SDX20, when an RSA encryption operation is called, the ce_util_to_unsigned_bin is invoked to convert the input buffer to unsigned binary. The ce_util_to_unsigned_bin function, instead of operating on the size of the unsigned character buffer that is passed, operates on the address - i.e. operates on "c" instead of "*c". Decrementing the address to check if it is less than zero means that the operation will always pass, since a pointer will never be less than zero, and may result in a buffer overflow.

The bug was discovered 04/04/2018. The weakness was disclosed 04/18/2018 (Website). It is possible to read the advisory at source.android.com. The identification of this vulnerability is CVE-2015-9138 since 08/16/2017. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 01/26/2020). It is expected to see the exploit prices for this product increasing in the near future.

The vulnerability was handled as a non-public zero-day exploit for at least 14 days. During that time the estimated underground price was around $25k-$100k.

Applying a patch is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 103671†). The entries VDB-83180, VDB-105483, VDB-105484 and VDB-105488 are pretty similar. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Smartphone Operating System

Vendor

• Google

Name

• Android

License

• free

Website

• Vendor: https://www.google.com/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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