CVE-2015-8777
Published: 20 January 2016
The process_envvars function in elf/rtld.c in the GNU C Library (aka glibc or libc6) before 2.23 allows local users to bypass a pointer-guarding protection mechanism via a zero value of the LD_POINTER_GUARD environment variable.
From the Ubuntu Security Team
Hector Marco and Ismael Ripoll discovered that the GNU C Library allowed the pointer-guarding protection mechanism to be disabled by honoring the LD_POINTER_GUARD environment variable across privilege boundaries. An local attacker could use this to exploit an existing vulnerability more easily.
Priority
Status
Package | Release | Status |
---|---|---|
eglibc Launchpad, Ubuntu, Debian |
precise |
Released
(2.15-0ubuntu10.14)
|
trusty |
Released
(2.19-0ubuntu6.8)
|
|
upstream |
Needed
|
|
vivid |
Does not exist
|
|
wily |
Does not exist
|
|
xenial |
Does not exist
|
|
yakkety |
Does not exist
|
|
zesty |
Does not exist
|
|
glibc Launchpad, Ubuntu, Debian |
precise |
Does not exist
|
trusty |
Does not exist
|
|
upstream |
Released
(2.21-6)
|
|
vivid |
Ignored
(end of life)
|
|
wily |
Released
(2.21-0ubuntu4.2)
|
|
xenial |
Not vulnerable
(2.23-0ubuntu1)
|
|
yakkety |
Not vulnerable
(2.23-0ubuntu1)
|
|
zesty |
Not vulnerable
(2.23-0ubuntu1)
|
|
Patches: upstream: https://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commit;h=a014cecd82b71b70a6a843e250e06b541ad524f7 |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 5.5 |
Attack vector | Local |
Attack complexity | Low |
Privileges required | Low |
User interaction | None |
Scope | Unchanged |
Confidentiality | None |
Integrity impact | High |
Availability impact | None |
Vector | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
References
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-8777
- http://www.openwall.com/lists/oss-security/2015/09/05/8
- http://www.openwall.com/lists/oss-security/2016/01/20/1
- http://hmarco.org/bugs/glibc_ptr_mangle_weakness.html
- https://ubuntu.com/security/notices/USN-2985-1
- NVD
- Launchpad
- Debian