OpenSSL SSL_free_buffers Use-After-Free Vulnerability
CVE-2024-4741 Published on November 13, 2024
Use After Free with SSL_free_buffers
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.
Vulnerability Analysis
CVE-2024-4741 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Dangling pointer Vulnerability?
Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.
CVE-2024-4741 has been classified to as a Dangling pointer vulnerability or weakness.
Products Associated with CVE-2024-4741
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Affected Versions
OpenSSL:- Version 3.3.0 and below 3.3.1 is affected.
- Version 3.2.0 and below 3.2.2 is affected.
- Version 3.1.0 and below 3.1.6 is affected.
- Version 3.0.0 and below 3.0.14 is affected.
- Version 1.1.1 and below 1.1.1y is affected.
- Version 1.1.1 and below 1.1.1y is affected.
- Version 3.0.0 and below 3.0.14 is affected.
- Version 3.1.0 and below 3.1.6 is affected.
- Version 3.2.0 and below 3.2.2 is affected.
- Version 3.3.0 and below 3.3.1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.