CVE-2020-1678: Vulnerability Analysis & Exploit Details

CVE-2020-1678 Vulnerability Summary

On Juniper Networks Junos OS and Junos OS Evolved platforms with EVPN configured, receipt of specific BGP packets causes a slow memory leak. If the memory is exhausted the rpd process might crash. If the issue occurs, the memory leak could be seen by executing the "show task memory detail | match policy | match evpn" command multiple times to check if memory (Alloc Blocks value) is increasing. root@device> show task memory detail | match policy | match evpn ------------------------ Allocator Memory Report ------------------------ Name | Size | Alloc DTXP Size | Alloc Blocks | Alloc Bytes | MaxAlloc Blocks | MaxAlloc Bytes Policy EVPN Params 20 24 3330678 79936272 3330678 79936272 root@device> show task memory detail | match policy | match evpn ------------------------ Allocator Memory Report ------------------------ Name | Size | Alloc DTXP Size | Alloc Blocks | Alloc Bytes | MaxAlloc Blocks | MaxAlloc Bytes Policy EVPN Params 20 24 36620255 878886120 36620255 878886120 This issue affects: Juniper Networks Junos OS 19.4 versions prior to 19.4R2; 20.1 versions prior to 20.1R1-S4, 20.1R2; Juniper Networks Junos OS Evolved: 19.4 versions; 20.1 versions prior to 20.1R1-S4-EVO, 20.1R2-EVO; 20.2 versions prior to 20.2R1-EVO; This issue does not affect: Juniper Networks Junos OS releases prior to 19.4R1. Juniper Networks Junos OS Evolved releases prior to 19.4R1-EVO.

CVE-2020-1678: Detailed Information and External References

EPSS

0.00060

EPSS %

0.27718

References

0.00060

• https://kb.juniper.net/JSA11075

CWE

CWE-400

CAPEC

0.00060

• XML Ping of the Death: An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
• Sustained Client Engagement: An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.
• Regular Expression Exponential Blowup: An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.

Vulnerable Configurations

• cpe:2.3:o:juniper:junos:19.4:r1:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos:19.4:r1:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos:19.4:r1-s1:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos:19.4:r1-s1:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos:19.4:r1-s2:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos:19.4:r1-s2:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos:20.1:r1:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos:20.1:r1:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos:20.1:r1-s1:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos:20.1:r1-s1:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos:20.1:r1-s2:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos:20.1:r1-s2:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos:20.1:r1-s3:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos:20.1:r1-s3:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos_os_evolved:19.4:r1:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos_os_evolved:19.4:r1:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos_os_evolved:19.4:r2:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos_os_evolved:19.4:r2:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos_os_evolved:19.4:r2-s1:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos_os_evolved:19.4:r2-s1:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos_os_evolved:20.1:-:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos_os_evolved:20.1:-:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos_os_evolved:20.1:r1:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos_os_evolved:20.1:r1:*:*:*:*:*:*
• cpe:2.3:o:juniper:junos_os_evolved:20.2:-:*:*:*:*:*:*
  cpe:2.3:o:juniper:junos_os_evolved:20.2:-:*:*:*:*:*:*

CVSS3 Source

sirt@juniper.net

CVSS3 Type

Primary

CVSS3 Vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H