CVE-2024-4741: Use-After-Free (CVSS 7.5)

Description

Issue summary: Calling the OpenSSL API function SSL_free_buffers may cause memory to be accessed that was previously freed in some situations Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, only applications that directly call the SSL_free_buffers function are affected by this issue. Applications that do not call this function are not vulnerable. Our investigations indicate that this function is rarely used by applications. The SSL_free_buffers function is used to free the internal OpenSSL buffer used when processing an incoming record from the network. The call is only expected to succeed if the buffer is not currently in use. However, two scenarios have been identified where the buffer is freed even when still in use. The first scenario occurs where a record header has been received from the network and processed by OpenSSL, but the full record body has not yet arrived. In this case calling SSL_free_buffers will succeed even though a record has only been partially processed and the buffer is still in use. The second scenario occurs where a full record containing application data has been received and processed by OpenSSL but the application has only read part of this data. Again a call to SSL_free_buffers will succeed even though the buffer is still in use. While these scenarios could occur accidentally during normal operation a malicious attacker could attempt to engineer a stituation where this occurs. We are not aware of this issue being actively exploited. The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-416 Use After Free

References

Other References

https://github.com/openssl/openssl/commit/704f725b96aa373ee45ecfb23f6abfe8be8d9177 https://github.com/openssl/openssl/commit/b3f0eb0a295f58f16ba43ba99dad70d4ee5c437d https://github.com/openssl/openssl/commit/c88c3de51020c37e8706bf7a682a162593053aac https://github.com/openssl/openssl/commit/e5093133c35ca82874ad83697af76f4b0f7e3bd8 https://github.openssl.org/openssl/extended-releases/commit/f7a045f3143fc6da2ee66bf52d8df04829590dd4 https://www.openssl.org/news/secadv/20240528.txt https://lists.debian.org/debian-lts-announce/2024/10/msg00033.html https://lists.debian.org/debian-lts-announce/2024/11/msg00000.html https://security.netapp.com/advisory/ntap-20240621-0004/

Frequently Asked Questions

What is CVE-2024-4741? +

Issue summary: Calling the OpenSSL API function SSL_free_buffers may cause memory to be accessed that was previously freed in some situations Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, only applications that directly call the SSL_free_buffers function are affected by this issue. Applications that do not call this function are not vulnerable. Our investigations indicate that this function is rarely used by applications. The SSL_free_buffers function is used to free the internal OpenSSL buffer used when processing an incoming record from the network. The call is only expected to succeed if the buffer is not currently in use. However, two scenarios have been identified where the buffer is freed even when still in use. The first scenario occurs where a record header has been received from the network and processed by OpenSSL, but the full record body has not yet arrived. In this case calling SSL_free_buffers will succeed even though a record has only been partially processed and the buffer is still in use. The second scenario occurs where a full record containing application data has been received and processed by OpenSSL but the application has only read part of this data. Again a call to SSL_free_buffers will succeed even though the buffer is still in use. While these scenarios could occur accidentally during normal operation a malicious attacker could attempt to engineer a stituation where this occurs. We are not aware of this issue being actively exploited. The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2024-4741? +

CVE-2024-4741 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

How do I check if I'm vulnerable to CVE-2024-4741? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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