SB2018051812 - Arch Linux update for lib32-libcurl-compat



SB2018051812 - Arch Linux update for lib32-libcurl-compat

Published: May 18, 2018

Security Bulletin ID SB2018051812
Severity
High
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Heap-based buffer overflow (CVE-ID: CVE-2018-1000300)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The weakness exists due to heap-based buffer overflow when closing down an FTP connection with very long server command replies. When doing FTP transfers, curl keeps a spare "closure handle" around internally that will be used when an FTP connection gets shut down since the original curl easy handle is then already removed. FTP server response data that gets cached from the original transfer might then be larger than the default buffer size (16 KB) allocated in the "closure handle", which can lead to buffer overwrite. A remote attacker can execute arbitrary code.

Successful exploitation of the vulnerability may result in system compromise.

2) Heap-based buffer over-read (CVE-ID: CVE-2018-1000301)

The vulnerability allows a remote attacker to obtain potentially sensitive information and cause DoS condition on the target system.

The weakness exists due to heap-based buffer over-read. When servers send RTSP responses back to curl, the data starts out with a set of headers. curl parses that data to separate it into a number of headers to deal with those appropriately and to find the end of the headers that signal the start of the "body" part. The function that splits up the response into headers is called Curl_http_readwrite_headers() and in situations where it can't find a single header in the buffer, it might end up leaving a pointer pointing into the buffer instead of to the start of the buffer which then later on may lead to an out of buffer read when code assumes that pointer points to a full buffer size worth of memory to use. A remote attacker can gain access to potentially sensitive information and cause the service to crash.

Remediation

Install update from vendor's website.