xkbcommon up to 0.8.1 Parser xkbcomp/expr.c ExprResolveLhs null pointer dereference
CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
---|---|---|
4.3 | $0-$5k | 0.00 |
A vulnerability was found in xkbcommon up to 0.8.1 and classified as problematic. This issue affects the function ExprResolveLhs
of the file xkbcomp/expr.c of the component Parser. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:
Unchecked NULL pointer usage in ExprResolveLhs in xkbcomp/expr.c in xkbcommon before 0.8.2 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file that triggers an xkb_intern_atom failure.
The bug was discovered 08/05/2018. The weakness was released 08/25/2018 (Website). It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2018-15861 since 08/24/2018. The exploitation is known to be easy. Attacking locally is a requirement. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.
The vulnerability was handled as a non-public zero-day exploit for at least 20 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 118505 (GLSA-201810-05 : xkbcommon: Multiple vulnerabilities), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Gentoo Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 197271 (Ubuntu Security Notification for Libxkbcommon Vulnerabilities (USN-3786-1)).
Upgrading to version 0.8.2 eliminates this vulnerability. A possible mitigation has been published 3 months after the disclosure of the vulnerability.
The vulnerability is also documented in the vulnerability database at Tenable (118505). Entries connected to this vulnerability are available at 123244, 123245, 123246 and 123247.
Product
Name
Version
License
CPE 2.3
CPE 2.2
CVSSv4
VulDB CVSS-B Score: 🔍VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 4.4VulDB Meta Temp Score: 4.3
VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔍
VulDB Reliability: 🔍
NVD Base Score: 5.5
NVD Vector: 🔍
CVSSv2
AV | AC | Au | C | I | A |
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💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
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unlock | unlock | unlock | unlock | unlock | unlock |
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍
NVD Base Score: 🔍
Exploiting
Class: Null pointer dereferenceCWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍
Local: Yes
Remote: No
Availability: 🔍
Status: Not defined
EPSS Score: 🔍
EPSS Percentile: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍
0-Day | unlock | unlock | unlock | unlock |
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Today | unlock | unlock | unlock | unlock |
Nessus ID: 118505
Nessus Name: GLSA-201810-05 : xkbcommon: Multiple vulnerabilities
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍
Qualys ID: 🔍
Qualys Name: 🔍
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Upgrade: xkbcommon 0.8.2
Patch: github.com
Timeline
08/05/2018 🔍08/24/2018 🔍
08/25/2018 🔍
08/25/2018 🔍
08/26/2018 🔍
10/30/2018 🔍
10/31/2018 🔍
05/04/2023 🔍
Sources
Advisory: RHSA-2019:2079Status: Confirmed
CVE: CVE-2018-15861 (🔍)
See also: 🔍
Entry
Created: 08/26/2018 08:58Updated: 05/04/2023 15:12
Changes: 08/26/2018 08:58 (74), 03/18/2020 10:52 (2), 05/04/2023 15:12 (5)
Complete: 🔍
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