CVE-2017-1000410 : Detail

CVE-2017-1000410

7.5
/
High
A01-Broken Access Control
0.23%V3
Network
2017-12-07
18h00 +00:00
2019-04-08
17h06 +00:00
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CVE Descriptions

The Linux kernel version 3.3-rc1 and later is affected by a vulnerability lies in the processing of incoming L2CAP commands - ConfigRequest, and ConfigResponse messages. This info leak is a result of uninitialized stack variables that may be returned to an attacker in their uninitialized state. By manipulating the code flows that precede the handling of these configuration messages, an attacker can also gain some control over which data will be held in the uninitialized stack variables. This can allow him to bypass KASLR, and stack canaries protection - as both pointers and stack canaries may be leaked in this manner. Combining this vulnerability (for example) with the previously disclosed RCE vulnerability in L2CAP configuration parsing (CVE-2017-1000251) may allow an attacker to exploit the RCE against kernels which were built with the above mitigations. These are the specifics of this vulnerability: In the function l2cap_parse_conf_rsp and in the function l2cap_parse_conf_req the following variable is declared without initialization: struct l2cap_conf_efs efs; In addition, when parsing input configuration parameters in both of these functions, the switch case for handling EFS elements may skip the memcpy call that will write to the efs variable: ... case L2CAP_CONF_EFS: if (olen == sizeof(efs)) memcpy(&efs, (void *)val, olen); ... The olen in the above if is attacker controlled, and regardless of that if, in both of these functions the efs variable would eventually be added to the outgoing configuration request that is being built: l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), (unsigned long) &efs); So by sending a configuration request, or response, that contains an L2CAP_CONF_EFS element, but with an element length that is not sizeof(efs) - the memcpy to the uninitialized efs variable can be avoided, and the uninitialized variable would be returned to the attacker (16 bytes).

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

Metrics

Metrics Score Severity CVSS Vector Source
V3.0 7.5 HIGH CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from routers).

Attack Complexity

This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.

Scope

Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.

Unchanged

An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same.

Base: Impact Metrics

The Impact metrics refer to the properties of the impacted component.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

None

There is no loss of integrity within the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

None

There is no impact to availability within the impacted component.

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability.

Environmental Metrics

[email protected]
V2 5 AV:N/AC:L/Au:N/C:P/I:N/A:N [email protected]

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version From (excluding) 3.2 To (excluding) 4.15

Linux>>Linux_kernel >> Version 4.15

Linux>>Linux_kernel >> Version 4.15

Linux>>Linux_kernel >> Version 4.15

Linux>>Linux_kernel >> Version 4.15

Linux>>Linux_kernel >> Version 4.15

Linux>>Linux_kernel >> Version 4.15

Linux>>Linux_kernel >> Version 4.15

Configuraton 0

Debian>>Debian_linux >> Version 8.0

Debian>>Debian_linux >> Version 9.0

Configuraton 0

Redhat>>Virtualization_host >> Version 4.0

Redhat>>Enterprise_linux_desktop >> Version 6.0

Redhat>>Enterprise_linux_desktop >> Version 7.0

Redhat>>Enterprise_linux_server >> Version 6.0

Redhat>>Enterprise_linux_server >> Version 7.0

Redhat>>Enterprise_linux_server_aus >> Version 7.6

Redhat>>Enterprise_linux_server_eus >> Version 7.4

Redhat>>Enterprise_linux_server_eus >> Version 7.6

Redhat>>Enterprise_linux_server_tus >> Version 7.4

Redhat>>Enterprise_linux_server_tus >> Version 7.6

Redhat>>Enterprise_linux_workstation >> Version 6.0

Redhat>>Enterprise_linux_workstation >> Version 7.0

References

http://seclists.org/oss-sec/2017/q4/357
Tags : mailing-list, x_refsource_MLIST
https://www.debian.org/security/2018/dsa-4082
Tags : vendor-advisory, x_refsource_DEBIAN
https://access.redhat.com/errata/RHSA-2018:1062
Tags : vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2018:0654
Tags : vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2018:1319
Tags : vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2018:0676
Tags : vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2018:1170
Tags : vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2018:1130
Tags : vendor-advisory, x_refsource_REDHAT
https://www.debian.org/security/2017/dsa-4073
Tags : vendor-advisory, x_refsource_DEBIAN
http://www.securityfocus.com/bid/102101
Tags : vdb-entry, x_refsource_BID
https://usn.ubuntu.com/3933-2/
Tags : vendor-advisory, x_refsource_UBUNTU
https://usn.ubuntu.com/3933-1/
Tags : vendor-advisory, x_refsource_UBUNTU