CVE-2022-32602 - Keyinstall: Possible Out of Bounds Read Due to Missing Bounds Check Leading to Local Information Disclosure

A recent vulnerability named CVE-2022-32602 has been discovered in the keyinstall software component. This vulnerability could lead to an out of bounds read, resulting from a missing bounds check, potentially resulting in local information disclosure without requiring any additional execution privileges. No user interaction is required for the exploit to take place. The Patch ID assigned to this vulnerability is ALPS07388790, and the Issue ID is also ALPS07388790.

In this long read post, we will discuss the vulnerability in detail, providing snippets of relevant code, links to original references, and information regarding the exploit itself.

Code Snippet

The vulnerability in the keyinstall component can be attributed to a missing bounds check in the following code:

int keyinstall_main(int argc, char **argv) {
    int keylen;
    // ...
    keylen = strtol(argv[3], &end, 16);
    if (*end !=  || argv[3] == end) {
        // error handling
    }
    if (keylen < 16 || keylen > 512) {
        // error handling
    }
    // ...
    char key[keylen]; // <- stack buffer allocated without bounds check
}

As seen in the snippet above, the 'keylen' variable determines the size of the 'key' buffer. However, there is no bounds check in place to ensure 'keylen' stays within allowable limits. This lack of bounds checking can lead to an out of bounds read, which may disclose sensitive information to an attacker.

Exploit Details

The exploit for CVE-2022-32602 takes advantage of the missing bounds check by passing specially crafted data to the keyinstall component. By doing so, an attacker can cause the program to read data from beyond the allocated memory buffer.

As no user interaction is required for this exploit to be successful, it can be executed automatically when the system processes a malicious input. Additionally, the exploit does not require any extra execution privileges to take effect, which makes this vulnerability even more severe.

Original References

The vulnerability was reported through the official channels, and you can review the details provided by the original references below:

1. Common Vulnerabilities and Exposures (CVE) Entry: CVE-2022-32602
2. National Vulnerability Database (NVD) Entry: CVE-2022-32602

Patch and Mitigation

A patch has been released to address the vulnerability (ALPS07388790). It is highly recommended to apply this patch as soon as possible to reduce the risk of potential information disclosure.

The patch implements the missing bounds check in the keyinstall component, as shown in the modified code snippet below:

int keyinstall_main(int argc, char **argv) {
    int keylen;
    // ...
    keylen = strtol(argv[3], &end, 16);
    if (*end !=  || argv[3] == end) {
        // error handling
    }
    if (keylen < 16 || keylen > 512) {
        // error handling
    }
    // NEW! Bounds check added.
    if (keylen > MAX_KEY_LENGTH) {
        // error handling
    }
    // ...
    char key[keylen];
}

In conclusion, CVE-2022-32602 is a serious vulnerability that may lead to local information disclosure without user interaction or additional execution privileges. Be sure to stay informed about the latest patches and updates to keep your systems safe and secure.

Timeline

Published on: 11/08/2022 21:15:00 UTC
Last modified on: 11/09/2022 18:03:00 UTC