CVE-2016-6354
Published: 21 September 2016
Heap-based buffer overflow in the yy_get_next_buffer function in Flex before 2.6.1 might allow context-dependent attackers to cause a denial of service or possibly execute arbitrary code via vectors involving num_to_read.
Notes
| Author | Note |
|---|---|
| mdeslaur | introduced in 2.5.36 by https://github.com/westes/flex/commit/9ba3187a537d6a58d345f2874d06087fd4050399 |
| sbeattie | redhat bug claims that it's not exploitable due to followup code also, simply replacing yy_size_t with int on num_to_read as in the upstream patch causes even more signed comparison warnings in flex generated sources; there's a comparison against a size_t variable in YY_INPUT for one. The "correct" fix for this likely includes the additional commit mentioned in the oss-security post. fixing will also require recompiling anything with generated code from the versions of flex in vivid through xenial. |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
flex Launchpad, Ubuntu, Debian |
artful |
Not vulnerable
(2.6.1-1)
|
| bionic |
Not vulnerable
(2.6.1-1)
|
|
| cosmic |
Not vulnerable
(2.6.1-1)
|
|
| disco |
Not vulnerable
(2.6.1-1)
|
|
| eoan |
Not vulnerable
(2.6.1-1)
|
|
| focal |
Not vulnerable
(2.6.1-1)
|
|
| groovy |
Not vulnerable
(2.6.1-1)
|
|
| hirsute |
Not vulnerable
(2.6.1-1)
|
|
| impish |
Not vulnerable
(2.6.1-1)
|
|
| jammy |
Not vulnerable
(2.6.1-1)
|
|
| kinetic |
Not vulnerable
(2.6.1-1)
|
|
| lunar |
Not vulnerable
(2.6.1-1)
|
|
| mantic |
Not vulnerable
(2.6.1-1)
|
|
| precise |
Not vulnerable
(2.5.35-10ubuntu3)
|
|
| trusty |
Does not exist
(trusty was not-affected [2.5.35-10.1ubuntu2])
|
|
| upstream |
Released
(2.6.1)
|
|
| wily |
Ignored
(end of life)
|
|
| xenial |
Needed
|
|
| yakkety |
Not vulnerable
(2.6.1-1)
|
|
| zesty |
Not vulnerable
(2.6.1-1)
|
|
|
Patches: upstream: https://github.com/westes/flex/commit/a5cbe929ac3255d371e698f62dc256afe7006466 |
||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.8 |
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |