NULL pointer dereference in linux-grsec (Alpine package)

1) NULL pointer dereference

EUVDB-ID: #VU33636

Risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2015-8551

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in Xen, when running on an x86 system and using Linux 3.1.x through 4.3.x as the driver domain, allows local guest administrators to hit BUG conditions and cause a denial of service (NULL pointer dereference and host OS crash) by leveraging a system with access to a passed-through MSI or MSI-X capable physical PCI device and a crafted sequence of XEN_PCI_OP_* operations, aka "Linux pciback missing sanity checks." <a href="http://cwe.mitre.org/data/definitions/476. A remote attacker can perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

linux-grsec (Alpine package): 3.14.51-r0 - 4.1.39-r0

CPE2.3

• cpe:2.3:o:alpine:linux-grsec_alpine_package:3.14.51-r0:*:*:*:*:alpine_linux:*:3.1
• cpe:2.3:o:alpine:linux-grsec_alpine_package:3.18.21-r2:*:*:*:*:alpine_linux:*:3.2
• cpe:2.3:o:alpine:linux-grsec_alpine_package:4.1.39-r0:*:*:*:*:alpine_linux:*:3.3

External links

https://git.alpinelinux.org/aports/commit/?id=a27a1dfef88c02a9ccc3443b59f9907d630dc82f
https://git.alpinelinux.org/aports/commit/?id=f4daf7f71ebcae92286f454de52a9eed33c1903d
https://git.alpinelinux.org/aports/commit/?id=1ab17fee115046c3923d9b2abeb1ff2677caaf76

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.