CVE-2021-0268

Junos OS: J-Web has an Improper Neutralization of CRLF Sequences in its HTTP Headers which allows an attacker to carry out multiple types of attacks.

Description

An Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting') weakness in J-web of Juniper Networks Junos OS leads to buffer overflows, segment faults, or other impacts, which allows an attacker to modify the integrity of the device and exfiltration information from the device without authentication. The weakness can be exploited to facilitate cross-site scripting (XSS), cookie manipulation (modifying session cookies, stealing cookies) and more. This weakness can also be exploited by directing a user to a seemingly legitimate link from the affected site. The attacker requires no special access or permissions to the device to carry out such attacks. This issue affects: Juniper Networks Junos OS: 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S3; 19.1 versions prior to 19.1R2-S2, 19.1R3-S2; 19.2 versions prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2, 19.4R3; 20.1 versions prior to 20.1R1-S2, 20.1R2. This issue does not affect Juniper Networks Junos OS versions prior to 18.1R1.

Remediation

Solution:

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

Workaround:

  • There are no viable workarounds for this issue other than disabling the J-Web service. To reduce the risk of exploitation utilize common security BCPs to limit the exploitable surface by limiting access to network and device to trusted systems, administrators, networks and hosts.

Categories

8.8
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.27%
Vendor Advisory juniper.net
Affected: Juniper Networks Junos OS
Published at:
Updated at:

References

Link Tags
https://kb.juniper.net/JSA11159 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-0268?
CVE-2021-0268 has been scored as a high severity vulnerability.
How to fix CVE-2021-0268?
To fix CVE-2021-0268: The following software releases have been updated to resolve this specific issue: 18.1R3-S11, 18.2R3-S5, 18.3R2-S4, 18.3R3-S3, 18.4R2-S5, 18.4R3-S3, 19.1R2-S2, 19.1R3-S2, 19.2R1-S5, 19.2R2, 19.3R3, 19.4R1-S3, 19.4R2, 19.4R3, 20.1R1-S2, 20.1R2, 20.2R1, and all subsequent releases.
Is CVE-2021-0268 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-0268 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-0268?
CVE-2021-0268 affects Juniper Networks Junos OS.
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