cbcvebase.
CVE-2017-13089
published 2017-10-27

CVE-2017-13089: The http.c:skip_short_body() function is called in some circumstances, such as when processing redirects. When the response is sent chunked in wget before…

PriorityP263high8.8CVSS 3.0
AVNACLPRNUIRSUCHIHAH
EPSS
79.86%
99.6th percentile
The http.c:skip_short_body() function is called in some circumstances, such as when processing redirects. 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 skip the chunk in pieces of 512 bytes by using the MIN() macro, but ends up passing the negative chunk length to connect.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.

Affected

11 ranges
VendorProductVersion rangeFixed in
debiandebian_linux
debiandebian_linux
debianwget< wget 1.19.2-1 (bookworm)wget 1.19.2-1 (bookworm)
gnuwget<= 1.19.1
gnuwget>= 0 < 1.19.2-11.19.2-1
gnuwget>= 0 < 1.19.2-11.19.2-1
gnuwget>= 0 < 1.19.2-11.19.2-1
gnuwget>= 0 < 1.19.2-11.19.2-1
gnuwget>= 0 < 1.15-1ubuntu1.14.04.31.15-1ubuntu1.14.04.3
gnuwget>= 0 < 1.17.1-1ubuntu1.31.17.1-1ubuntu1.3
gnu_projectwget

Detection & IOCsextracted from sources · hover to see the quote

  • Trigger condition: the vulnerability is exercised when a malicious HTTP server sends a chunked-encoded response with a negative chunk length value during redirect processing, causing skip_short_body() to pass an attacker-controlled length to fd_read()
  • Attack vector: a remote attacker must trick a user into connecting to a malicious HTTP server that returns a specially crafted chunked HTTP response (e.g., during a redirect), enabling stack-based buffer overflow and potential arbitrary code execution
  • Vulnerable code path: http.c:skip_short_body() called during redirect processing is the entry point; monitor for wget processes handling redirected chunked HTTP responses from untrusted servers
  • ·Only wget versions before 1.19.2 are vulnerable; Red Hat Enterprise Linux 5 and 6 shipped versions are NOT affected — only RHEL 7 is affected
  • ·The vulnerability only triggers when the HTTP response uses chunked transfer encoding; non-chunked responses do not exercise the vulnerable code path

CVSS provenance

nvdv3.08.8HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.09.3CRITICALAV:N/AC:M/Au:N/C:C/I:C/A:C
osv8.8HIGH
vendor_debian8.8HIGH
vendor_redhat8.8HIGH
vendor_ubuntu8.1HIGH
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