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;
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.
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.
| Product | Vulnerable range | Fixed version | Advisory |
|---|---|---|---|
| Juniper Networks Junos OS | >=18.1<18.1R3-S11 | 18.1R3-S11 | advisory ↗ |
| Juniper Networks Junos OS | >=18.2<18.2R3-S5 | 18.2R3-S5 | advisory ↗ |
| Juniper Networks Junos OS | >=18.3<18.3R2-S4, 18.3R3-S3 | 18.3R2-S4, 18.3R3-S3 | advisory ↗ |
| Juniper Networks Junos OS | >=18.4<18.4R2-S5, 18.4R3-S3 | 18.4R2-S5, 18.4R3-S3 | advisory ↗ |
| Juniper Networks Junos OS | >=19.1<19.1R2-S2, 19.1R3-S2 | 19.1R2-S2, 19.1R3-S2 | advisory ↗ |
| Juniper Networks Junos OS | >=19.2<19.2R1-S5, 19.2R2 | 19.2R1-S5, 19.2R2 | advisory ↗ |
| Juniper Networks Junos OS | >=19.3<19.3R3 | 19.3R3 | advisory ↗ |
| Juniper Networks Junos OS | >=19.4<19.4R1-S3, 19.4R2, 19.4R3 | 19.4R1-S3, 19.4R2, 19.4R3 | advisory ↗ |
| Juniper Networks Junos OS | >=20.1<20.1R1-S2, 20.1R2 | 20.1R1-S2, 20.1R2 | advisory ↗ |