CVE-2017-13090

The retr.c:fd_read_body() function is called when processing OK responses. When the response is sent chunked in wget before 1.19.2, the chunk parser uses strtol() to read each chunk's length, but doesn't check that the chunk length is a non-negative number. The code then tries to read the chunk in pieces of 8192 bytes by using the MIN() macro, but ends up passing the negative chunk length to retr.c:fd_read(). As fd_read() takes an int argument, the high 32 bits of the chunk length are discarded, leaving fd_read() with a completely attacker controlled length argument. The attacker can corrupt malloc metadata after the allocated buffer.

• CVE ID
• CVE-2017-13090

• Assigner
• cret@cert.org

• Vulnerability Status
• Modified

• Published Version
• 2017-10-27T19:29:00

• Last Modified Date
• 2017-12-30T02:29:01

• Version
• 2.0

• Vector String
• AV:N/AC:M/Au:N/C:C/I:C/A:C

• Access Vector
• NETWORK

• Access Compatibility
• MEDIUM

• Authentication
• NONE

• Confidentiality Impact
• COMPLETE

• Integrity Impact
• COMPLETE

• Availability Impact
• COMPLETE

• Base Score
• 9.3

• Severity
• HIGH

• Exploitability Score
• 8.6

• Impact Score
• 10

• Version
• 3.0

• Vector String
• CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

• Attack Vector
• NETWORK

• Attack Compatibility
• LOW

• Privileges Required
• NONE

• User Interaction
• REQUIRED

• Scope
• UNCHANGED

• Confidentiality Impact
• HIGH

• Availability Impact
• HIGH

• Base Score
• 8.8

• Base Severity
• HIGH

• Exploitability Score
• 2.8

• Impact Score
• 5.9