Linux Kernel up to 5.0.7 fs/binfmt_aout.c install_exec_creds race condition ⚔ [Disputed]

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.0.7. It has been declared as problematic. The affected element is the function install_exec_creds of the file fs/binfmt_aout.c. Such manipulation leads to race condition. This vulnerability is referenced as CVE-2019-11191. The attack can only be performed from a local environment. No exploit is available. The real existence of this vulnerability is still doubted at the moment.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.0.7 (Operating System). It has been rated as problematic. Affected by this issue is the function install_exec_creds of the file fs/binfmt_aout.c. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality, integrity, and availability. CVE summarizes:

The Linux kernel through 5.0.7, when CONFIG_IA32_AOUT is enabled and ia32_aout is loaded, allows local users to bypass ASLR on setuid a.out programs (if any exist) because install_exec_creds() is called too late in load_aout_binary() in fs/binfmt_aout.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat.

The bug was discovered 04/18/2019. The weakness was published 04/12/2019 (Website). The advisory is available at securityfocus.com. This vulnerability is handled as CVE-2019-11191 since 04/11/2019. Local access is required to approach this attack. Required for exploitation is a simple authentication. Technical details are known, but there is no available exploit.

The real existence of this vulnerability is still doubted at the moment. The commercial vulnerability scanner Qualys is able to test this issue with plugin 197486 (Ubuntu Security Notification for Linux, Linux-aws, Linux-kvm, Linux-raspi2, Linux-snapdragon Vulnerabilities (USN-4008-1)).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at SecurityFocus (BID 107890†). Similar entries are available at VDB-82964, VDB-107092, VDB-115786 and VDB-131935. If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.0.0
• 5.0.1
• 5.0.2
• 5.0.3
• 5.0.4
• 5.0.5
• 5.0.6
• 5.0.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion