CVE-2021-0217 Detail

CVE-2021-0217

Score / Severity

7.4

High

CVE Descriptions

Junos OS: EX Series and QFX Series: Memory leak issue processing specific DHCP packets

A vulnerability in processing of certain DHCP packets from adjacent clients on EX Series and QFX Series switches running Juniper Networks Junos OS with DHCP local/relay server configured may lead to exhaustion of DMA memory causing a Denial of Service (DoS). Over time, exploitation of this vulnerability may cause traffic to stop being forwarded, or to crashing of the fxpc process. When Packet DMA heap utilization reaches 99%, the system will become unstable. Packet DMA heap utilization can be monitored through the following command: user@junos# request pfe execute target fpc0 timeout 30 command "show heap" ID Base Total(b) Free(b) Used(b) % Name -- ---------- ----------- ----------- ----------- --- ----------- 0 213301a8 536870488 387228840 149641648 27 Kernel 1 91800000 8388608 3735120 4653488 55 DMA 2 92000000 75497472 74452192 1045280 1 PKT DMA DESC 3 d330000 335544320 257091400 78452920 23 Bcm_sdk 4 96800000 184549376 2408 184546968 99 Packet DMA <--- 5 903fffe0 20971504 20971504 0 0 Blob An indication of the issue occurring may be observed through the following log messages: Dec 10 08:07:00.124 2020 hostname fpc0 brcm_pkt_buf_alloc:523 (buf alloc) failed allocating packet buffer Dec 10 08:07:00.126 2020 hostname fpc0 (buf alloc) failed allocating packet buffer Dec 10 08:07:00.128 2020 hostname fpc0 brcm_pkt_buf_alloc:523 (buf alloc) failed allocating packet buffer Dec 10 08:07:00.130 2020 hostnameC fpc0 (buf alloc) failed allocating packet buffer This issue affects Juniper Networks Junos OS on EX Series and QFX Series: 17.4R3 versions prior to 17.4R3-S3; 18.1R3 versions between 18.1R3-S6 and 18.1R3-S11; 18.2R3 versions prior to 18.2R3-S6; 18.3R3 versions prior to 18.3R3-S4; 18.4R2 versions prior to 18.4R2-S5; 18.4R3 versions prior to 18.4R3-S6; 19.1 versions between 19.1R2 and 19.1R3-S3; 19.2 versions prior to 19.2R3-S1; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R2-S2, 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S2, 20.2R2. Junos OS versions prior to 17.4R3 are unaffected by this vulnerability.

CVE Solutions

The following software releases have been updated to resolve this specific issue: Junos OS 17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.3R3-S4, 18.4R2-S5, 18.4R2-S7, 18.4R3-S6, 19.1R1-S6, 19.1R3-S3, 19.2R3-S1, 19.3R2-S5, 19.3R3, 19.4R2-S2, 19.4R3, 20.1R2, 20.2R1-S2, 20.2R2, 20.3R1, and all subsequent releases.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-119	Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
CWE-770	Allocation of Resources Without Limits or Throttling The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.1	7.4	HIGH	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H More informations 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. Adjacent The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone). 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. None The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack. 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. Changed An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities. 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. 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. High There is a total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). 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.
V2	3.3		AV:A/AC:L/Au:N/C:N/I:N/A:P	[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.

EPSS First.org

Products Mentioned

Configuraton 0

Juniper>>Junos >> Version 17.4

Juniper>>Junos >> Version 17.4 (Open CPE detail)

Juniper>>Junos >> Version 17.4

Juniper>>Junos >> Version 17.4 (Open CPE detail)

Juniper>>Junos >> Version 17.4

Juniper>>Junos >> Version 17.4 (Open CPE detail)

Juniper>>Junos >> Version 18.1

Juniper>>Junos >> Version 18.1 (Open CPE detail)

Juniper>>Junos >> Version 18.1

Juniper>>Junos >> Version 18.1 (Open CPE detail)

Juniper>>Junos >> Version 18.1

Juniper>>Junos >> Version 18.1 (Open CPE detail)

Juniper>>Junos >> Version 18.1

Juniper>>Junos >> Version 18.1 (Open CPE detail)

Juniper>>Junos >> Version 18.2

Juniper>>Junos >> Version 18.2 (Open CPE detail)

Juniper>>Junos >> Version 18.2

Juniper>>Junos >> Version 18.2 (Open CPE detail)

Juniper>>Junos >> Version 18.2

Juniper>>Junos >> Version 18.2 (Open CPE detail)

Juniper>>Junos >> Version 18.2

Juniper>>Junos >> Version 18.2 (Open CPE detail)

Juniper>>Junos >> Version 18.2

Juniper>>Junos >> Version 18.2 (Open CPE detail)

Juniper>>Junos >> Version 18.2

Juniper>>Junos >> Version 18.2 (Open CPE detail)

Juniper>>Junos >> Version 18.3

Juniper>>Junos >> Version 18.3 (Open CPE detail)

Juniper>>Junos >> Version 18.3

Juniper>>Junos >> Version 18.3 (Open CPE detail)

Juniper>>Junos >> Version 18.3

Juniper>>Junos >> Version 18.3 (Open CPE detail)

Juniper>>Junos >> Version 18.3

Juniper>>Junos >> Version 18.3 (Open CPE detail)

Juniper>>Junos >> Version 18.4

Juniper>>Junos >> Version 18.4 (Open CPE detail)

Juniper>>Junos >> Version 18.4

Juniper>>Junos >> Version 18.4 (Open CPE detail)

Juniper>>Junos >> Version 18.4

Juniper>>Junos >> Version 18.4 (Open CPE detail)

Juniper>>Junos >> Version 18.4

Juniper>>Junos >> Version 18.4 (Open CPE detail)

Juniper>>Junos >> Version 18.4

Juniper>>Junos >> Version 18.4 (Open CPE detail)

Juniper>>Junos >> Version 19.1

Juniper>>Junos >> Version 19.1 (Open CPE detail)

Juniper>>Junos >> Version 19.1

Juniper>>Junos >> Version 19.1 (Open CPE detail)

Juniper>>Junos >> Version 19.1

Juniper>>Junos >> Version 19.1 (Open CPE detail)

Juniper>>Junos >> Version 19.1

Juniper>>Junos >> Version 19.1 (Open CPE detail)