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                             CERT-Renater

                 Note d'Information No. 2020/VULN425
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DATE                : 22/07/2020

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Junos OS versions 17.4, 18.1, 18.2, 18.2X75, 18.3,
                                18.4, 19.1, 19.2, 19.3, 19.4.

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https://kb.juniper.net/InfoCenter/index?page=content&id=JSA11040&cat=SIRT_1&actp=LIST
_____________________________________________________________________



2020-07 Security Bulletin: Junos OS: Kernel crash (vmcore) or FPC crash
due to mbuf leak (CVE-2020-1653)


Article ID: JSA11040 SECURITY_ADVISORIES Last Updated: 21 Jul
2020Version: 3.0

Product Affected:
This issue affects Junos OS 17.4, 18.1, 18.2, 18.2X75, 18.3, 18.4, 19.1,
19.2, 19.3, 19.4.


Problem:

On Juniper Networks Junos OS devices, a stream of TCP packets sent to
the Routing Engine (RE) may cause mbuf leak which can lead to Flexible
PIC Concentrator (FPC) crash or the system to crash and restart
(vmcore).

This issue can be trigged by IPv4 or IPv6 and it is caused only by TCP
packets.

This issue is not related to any specific configuration and it affects
Junos OS releases starting from 17.4R1.

However, this issue does not affect Junos OS releases prior to 18.2R1
when Nonstop active routing (NSR) is configured [edit routing-options
nonstop-routing].

The number of mbufs is platform dependent.

The following command provides the number of mbufs counter that are
currently in use and maximum number of mbufs that can be allocated on a
platform:
user@host> show system buffers
2437/3143/5580 mbufs in use (current/cache/total)

Once the device runs out of mbufs, the FPC crashes or the vmcore occurs
and the device might become inaccessible requiring a manual restart.

This issue affects Juniper Networks Junos OS

17.4 versions prior to 17.4R2-S11, 17.4R3-S2;

18.1 versions prior to 18.1R3-S10;

18.2 versions prior to 18.2R2-S7, 18.2R3-S5;

18.2X75 versions prior to 18.2X75-D41, 18.2X75-D420.12, 18.2X75-D51,
18.2X75-D60, 18.2X75-D34;

18.3 versions prior to 18.3R2-S4, 18.3R3-S2;

18.4 versions prior to 18.4R1-S7, 18.4R2-S4, 18.4R3-S1;

19.1 versions prior to 19.1R1-S5, 19.1R2-S1, 19.1R3;

19.2 versions prior to 19.2R1-S5, 19.2R2;

19.3 versions prior to 19.3R2-S3, 19.3R3;

19.4 versions prior to 19.4R1-S2, 19.4R2.

Versions of Junos OS prior to 17.4R1 are unaffected by this
vulnerability.


Juniper SIRT is not aware of any malicious exploitation of this
vulnerability.

This issue was seen during production usage.

This issue has been assigned CVE-2020-1653.


Solution:
The following software releases have been updated to resolve this
specific issue: 17.4R2-S11, 17.4R3-S2, 18.1R3-S10, 18.2R2-S7, 18.2R3-S5,
18.2X75-D41, 18.2X75-D420.12, 18.2X75-D51, 18.2X75-D60, 18.2X75-D34,
18.3R2-S4, 18.3R3-S2, 18.4R1-S7, 18.4R2-S4, 18.4R3-S1, 19.1R1-S5,
19.1R2-S1, 19.1R3, 19.2R1-S5, 19.2R2, 19.3R2-S3, 19.3R3, 19.4R1-S2,
19.4R2, 20.1R1, and all subsequent releases.

This issue is being tracked as 1468183.


Workaround:

There are no viable workarounds for this issue, however having the DDoS
feature enabled and using the firewall filter to limit incoming packet
towards the RE only from trusted networks and host help to mitigate this
issue.

The following command can be used to check if DDoS feature is enabled:
user@host> show ddos-protection statistics
  DDOS protection global statistics:
  Policing on routing engine: Yes <--- must be "Yes"
  Policing on FPC: Yes
  <snip>

Implementation:
Software releases or updates are available for download at
https://www.juniper.net/support/downloads/.


Modification History:

​2020-07-08: Initial publication
2020-07-21: Adding the PR reference


CVSS Score:
7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Severity Level:
High


Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446
"Common Vulnerability Scoring System (CVSS) and Juniper's Security
Advisories."

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