Vulnerability CVE-2019-19726


Published: 2019-12-12

Description:
OpenBSD through 6.6 allows local users to escalate to root because a check for LD_LIBRARY_PATH in setuid programs can be defeated by setting a very small RLIMIT_DATA resource limit. When executing chpass or passwd (which are setuid root), _dl_setup_env in ld.so tries to strip LD_LIBRARY_PATH from the environment, but fails when it cannot allocate memory. Thus, the attacker is able to execute their own library code as root.

See advisories in our WLB2 database:
Topic
Author
Date
High
OpenBSD 6.x Dynamic Loader Privilege Escalation
Qualys
17.12.2019
High
OpenBSD Dynamic Loader chpass Privilege Escalation
Brendan Coles
29.12.2019

Type:

CWE-269

(Improper Privilege Management)

CVSS2 => (AV:L/AC:L/Au:N/C:C/I:C/A:C)

CVSS Base Score
Impact Subscore
Exploitability Subscore
7.2/10
10/10
3.9/10
Exploit range
Attack complexity
Authentication
Local
Low
No required
Confidentiality impact
Integrity impact
Availability impact
Complete
Complete
Complete
Affected software
Openbsd -> Openbsd 

 References:
http://packetstormsecurity.com/files/155658/Qualys-Security-Advisory-OpenBSD-Dynamic-Loader-Privilege-Escalation.html
http://seclists.org/fulldisclosure/2019/Dec/31
https://seclists.org/bugtraq/2019/Dec/25
https://www.openbsd.org/errata66.html
https://www.openwall.com/lists/oss-security/2019/12/11/9

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