Linux Vulnerabilities of the Week: June 14, 2021

1. The libX11 (<1.7.1) missing validation flaw affecting Red Hat Enterprise Linux 7 and 8

Severity: Critical         CVSS Score: 9.8

Exploiting this vulnerability, an attacker can inject X11 protocol commands on X clients, and potentially execute arbitrary code with permissions of the application compiled with libX11.

The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Syxscore Risk Alert

This vulnerability has a critical risk as this can be exposed over any network, with low complexity, no privileges, and without user interaction.

• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope (Jump Point): Unchanged

CVE Reference(s): CVE-2021-31535

2. Buffer overrun flaw in PostgreSQL

Severity: Important    CVSS Score: 8.8

This is a vulnerability in PostgreSQL in versions before 13.3, before 12.7, before 11.12, before 10.17, and before 9.6.22.

Due to missing bound checks during an SQL array modification process, authenticated database users can write arbitrary bytes to a wide area of server memory.

The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Syxscore Risk Alert

This vulnerability has a major risk as although this requires some privileges, it can be exposed over any network with a low complexity attack, and without user interaction.

• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low
• User Interaction: None
• Scope (Jump Point): Unchanged

CVE Reference(s): CVE-2021-32027

3. The Linux kernel io_uring vulnerability

Severity: Important    CVSS Score: 8.8

The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being used in mem_rw when reading /proc/<PID>/mem. This could allow a local attacker with low privileges to create a heap overflow and execute arbitrary code.

The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Syxscore Risk Alert

This vulnerability has a major risk as although this needs access to the same network as the device, the attack is of low complexity, needs low privileges, and no user interaction. Besides, this flaw allows a lateral attack to be made, due to the changed jump point.

• Attack Vector: Local
• Attack Complexity: Low
• Privileges Required: Low
• User Interaction: None
• Scope (Jump Point): Changed

CVE Reference(s): CVE-2021-3491

4. Improper input validation flaw in Squid

Severity: Important    CVSS Score: 8.6

This is a vulnerability in Squid through 4.13 and 5.x through 5.0.4. Because of improper validation while parsing the request URI, squid is vulnerable to HTTP request smuggling.

Exploiting this flaw, a trusted client can perform an HTTP request smuggling attack and access services otherwise forbidden by squid.

The highest threat from this vulnerability is to data confidentiality.

Syxscore Risk Alert

This vulnerability has a major risk as this can be exposed over any network, with low complexity, no privileges, and without user interaction. Besides, this flaw allows a lateral attack to be made, due to the changed jump point.

• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope (Jump Point): Changed

CVE Reference(s): CVE-2020-25097

5. The runc (<1.0.0-rc95) package vulnerability

Severity: Important    CVSS Score: 8.5

The runc package is vulnerable to a symlink exchange attack. To exploit the vulnerability, an attacker must create multiple containers with a fairly specific mount configuration. If an attack is successful, it can result in the host filesystem being bind-mounted into the container.

The highest threat from this vulnerability is to data confidentiality and integrity as well as to system availability.

Syxscore Risk Alert

This vulnerability has a high risk as although it can be exploited only with a complex attack, it can be exposed over any network, needs low privileges, and no user interaction. Besides, this flaw allows a lateral attack to be made, due to the changed jump point.

• Attack Vector: Network
• Attack Complexity: High
• Privileges Required: Low
• User Interaction: None
• Scope (Jump Point): Changed

CVE Reference(s): CVE-2021-30465

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