SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-0268

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…

CRITICAL 9.3EPSS 0.85%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.85%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
9.3 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
EPSS
0.85% probability · 56th percentile
CISA KEV
Not listed
Weakness
CWE-79, CWE-113, CWE-120, CWE-74
Affected
juniper/junos
Source
sirt@juniper.net

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.