Vulnerability Report

CVE-2019-18425

Title: Debian Debian Linux Auth Bypass

Auth Bypass

Proof Of Concept

No public PoC currently indexed for CVE-2019-18425.

CWE Category CWE-269
Published Date Oct 31, 2019
Modified Date Nov 21, 2024
Exploit Status Not Found
Score 9.8 CVSS v3.1
Exploit Probability (EPSS)
2.55%

Vulnerability Summary

CVE-2019-18425: An issue was discovered in Xen through 4.12.x allowing 32-bit PV guest OS users to gain guest OS privileges by installing and using descriptors. There is missing descriptor table limit checking in x86 PV emulation. When emulating certain PV guest operations, descriptor table accesses are performed by the emulating code. Such accesses should respect the guest specified limits, unless otherwise guaranteed to fail in such a case. Without this, emulation of 32-bit guest user mode calls through call gates would allow guest user mode to install and then use descriptors of their choice, as long as the guest kernel did not itself install an LDT. (Most OSes don't install any LDT by default). 32-bit PV guest user mode can elevate its privileges to that of the guest kernel. Xen versions from at least 3.2 onwards are affected. Only 32-bit PV guest user mode can leverage this vulnerability. HVM, PVH, as well as 64-bit PV guests cannot leverage this vulnerability. Arm systems are unaffected.

Impacted Vendors

D
debian 1
C
cisco 1
R
redhat 1
X
xensource_inc 1
X
xen 1
F
fedoraproject 1
G
gowondesigns 1
O
opensuse 1

Reference Links

http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html http://www.openwall.com/lists/oss-security/2019/10/31/2 http://xenbits.xen.org/xsa/advisory-298.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/ https://seclists.org/bugtraq/2020/Jan/21 https://security.gentoo.org/glsa/202003-56 https://www.debian.org/security/2020/dsa-4602 http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00037.html http://www.openwall.com/lists/oss-security/2019/10/31/2 http://xenbits.xen.org/xsa/advisory-298.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/ https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/ https://seclists.org/bugtraq/2020/Jan/21 https://security.gentoo.org/glsa/202003-56 https://www.debian.org/security/2020/dsa-4602
CVSS v3.1
Source Entity [email protected]
Severity CRITICAL
9.8
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2.0
Source Entity [email protected]
Severity HIGH
9.3
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:M/Au:N/C:C/I:C/A:C

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2019-18425 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Stack

No specific products linked.