CVE Vulnerabilities


Cleartext Transmission of Sensitive Information

Published: Feb 23, 2023 | Modified: Mar 27, 2024
CVSS 3.x
CVSS 2.x
4.2 LOW

A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality to behave incorrectly when multiple URLs are requested in parallel. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. This HSTS mechanism would however surprisingly fail when multiple transfers are done in parallel as the HSTS cache file gets overwritten by the most recentlycompleted transfer. A later HTTP-only transfer to the earlier host name would then not get upgraded properly to HSTS.


The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

Affected Software

Name Vendor Start Version End Version
Curl Haxx 7.77.0 (including) 7.88.0 (excluding)
Curl Ubuntu devel *
Curl Ubuntu jammy *
Curl Ubuntu kinetic *
Curl Ubuntu lunar *
Curl Ubuntu trusty *
Curl Ubuntu upstream *
Curl Ubuntu xenial *
JBCS httpd 2.4.51.sp2 RedHat curl *
JBoss Core Services for RHEL 8 RedHat jbcs-httpd24-curl-0:8.0.1-1.el8jbcs *
JBoss Core Services on RHEL 7 RedHat jbcs-httpd24-curl-0:8.0.1-1.el7jbcs *

Extended Description

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.

Potential Mitigations