CVE-2017-13089CWE-121

GNU Wget: stack overflow in HTTP protocol handling

High · published October 27, 2017

Patch now

High probability of exploitation

CVSS calls it high at 8.8. It sits in the 99.6th percentile for exploit probability.

CVSS v3.0
8.8
EPSS
80%
Percentile
99.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.0
8.8 · HIGH
Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.79855 · 99.6th percentile
Weakness
CWE-121 · Stack-based Buffer Overflow
Published
2017-10-27T19:00Z
EPSS history
Timeline
  • 27 OCT 19:00Z
    GNU Wget: stack overflow in HTTP protocol handling
    cvelistv5