In curl before 7.86.0, the HSTS check could be bypassed to trick it into staying with HTTP. Using its HSTS support, curl can be instructed to use HTTPS directly (instead of using an insecure cleartext HTTP step) even when HTTP is provided in the URL. This mechanism could be bypassed if the host name in the given URL uses IDN characters that get replaced with ASCII counterparts as part of the IDN conversion, e.g., using the character UTF-8 U+3002 (IDEOGRAPHIC FULL STOP) instead of the common ASCII full stop of U+002E (.). The earliest affected version is 7.77.0 2021-05-26.
The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Curl | Haxx | 7.77.0 (including) | 7.86.0 (excluding) |
| JBoss Core Services for RHEL 8 | RedHat | jbcs-httpd24-curl-0:7.86.0-2.el8jbcs | * |
| JBoss Core Services on RHEL 7 | RedHat | jbcs-httpd24-curl-0:7.86.0-2.el7jbcs | * |
| Red Hat JBoss Core Services 1 | RedHat | curl | * |
| Curl | Ubuntu | devel | * |
| Curl | Ubuntu | jammy | * |
| Curl | Ubuntu | kinetic | * |
| Curl | Ubuntu | trusty | * |
| Curl | Ubuntu | xenial | * |
Many communication channels can be “sniffed” (monitored) by adversaries during data transmission. For example, in networking, packets can traverse many intermediary nodes from the source to the destination, whether across the internet, an internal network, the cloud, etc. Some actors might have privileged access to a network interface or any link along the channel, such as a router, but they might not be authorized to collect the underlying data. As a result, network traffic could be sniffed by adversaries, spilling security-critical data. Applicable communication channels are not limited to software products. Applicable channels include hardware-specific technologies such as internal hardware networks and external debug channels, supporting remote JTAG debugging. When mitigations are not applied to combat adversaries within the product’s threat model, this weakness significantly lowers the difficulty of exploitation by such adversaries. When full communications are recorded or logged, such as with a packet dump, an adversary could attempt to obtain the dump long after the transmission has occurred and try to “sniff” the cleartext from the recorded communications in the dump itself.