OpenBSD update for xkbcomp
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Input validation error
EUVDB-ID: #VU15753
Risk: Low
CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2018-15853
CWE-ID:
CWE-20 - Improper input validation
Exploit availability: No
DescriptionThe vulnerability allows a local attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to endless recursion exists in xkbcomp/expr.c during insufficient validation of user-supplied input. A local attacker can supply a specially crafted keymap file, trigger boolean negation and cause the application to crash.
MitigationInstall update from vendor's website.
Vulnerable software versionsOpenBSD: 7.7 - 7.8
CPE2.3 External linkshttps://www.openbsd.org/errata78.html#009
https://www.openbsd.org/errata77.html#016
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Null pointer dereference
EUVDB-ID: #VU15925
Risk: Low
CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2018-15859
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a local attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to NULL pointer usage condition by the ExprResolveLhs function, as defined in the xkbcomp/expr.c source code file. A local attacker can submit a specially crafted keymap file that submits malicious input, trigger NULL pointer dereference and cause the application to crash.
MitigationInstall update from vendor's website.
Vulnerable software versionsOpenBSD: 7.7 - 7.8
CPE2.3 External linkshttps://www.openbsd.org/errata78.html#009
https://www.openbsd.org/errata77.html#016
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
3) Null pointer dereference
EUVDB-ID: #VU15927
Risk: Low
CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2018-15861
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a local attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to NULL pointer usage condition by the ExprResolveLhs function, as defined in the xkbcomp/expr.c source code file. A local attacker can submit a specially crafted keymap file that submits malicious input, trigger an xkb_intern_atom failure and cause the application to crash.
MitigationInstall update from vendor's website.
Vulnerable software versionsOpenBSD: 7.7 - 7.8
CPE2.3 External linkshttps://www.openbsd.org/errata78.html#009
https://www.openbsd.org/errata77.html#016
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
4) Null pointer dereference
EUVDB-ID: #VU15929
Risk: Low
CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]
CVE-ID: CVE-2018-15863
CWE-ID:
CWE-476 - NULL Pointer Dereference
Exploit availability: No
DescriptionThe vulnerability allows a local attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to NULL pointer usage condition by the ResolveStateAndPredicate function, as defined in the xkbcomp/compat.c source code file. A local attacker can submit a specially crafted keymap file that submits malicious input to an affected system with a no-op modmaskexpression, trigger NULL pointer dereference and cause the application to crash.
MitigationInstall update from vendor's website.
Vulnerable software versionsOpenBSD: 7.7 - 7.8
CPE2.3 External linkshttps://www.openbsd.org/errata78.html#009
https://www.openbsd.org/errata77.html#016
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
