CVE-2022-4450 — openssl-src
HIGHCVE-2022-4450 is a high-severity (CVSS 7.5) CWE-415 vulnerability in openssl-src. EPSS puts its 30-day exploitation probability at 20.4% (97th percentile). A fix is available for openssl-src — see the affected versions and patch details below.
Double free after calling PEM_read_bio_ex
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-4450.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2022-4450 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
openssl-src🦀openssl-srcReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
The function PEM_read_bio_ex() reads a PEM file from a BIO and parses and decodes the "name" (e.g. "CERTIFICATE"), any header data and the payload data. If the function succeeds then the "name_out", "header" and "data" arguments are populated with pointers to buffers containing the relevant decoded data. The caller is responsible for freeing those buffers. It is possible to construct a PEM file that results in 0 bytes of payload data. In this case PEM_read_bio_ex() will return a failure code but will populate the header argument with a pointer to a buffer that has already been freed. If the caller also frees this buffer then a double free will occur. This will most likely lead to a crash. This could be exploited by an attacker who has the ability to supply malicious PEM files for parsing to achieve a denial of service attack.
The functions PEM_read_bio() and PEM_read() are simple wrappers around PEM_read_bio_ex() and therefore these functions are also directly affected.
These functions are also called indirectly by a number of other OpenSSL functions including PEM_X509_INFO_read_bio_ex() and SSL_CTX_use_serverinfo_file() which are also vulnerable. Some OpenSSL internal uses of these functions are not vulnerable because the caller does not free the header argument if PEM_read_bio_ex() returns a failure code. These locations include the PEM_read_bio_TYPE() functions as well as the decoders introduced in OpenSSL 3.0.
The OpenSSL asn1parse command line application is also impacted by this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | openssl-src | all versions | 111.25.0cargo update -p openssl-src --precise 111.25.0 |
| 🦀crates.io | openssl-src | ≥ 300.0.0&&< 300.0.12 | 300.0.12cargo update -p openssl-src --precise 300.0.12 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openssl-src, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openssl-src to 111.25.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-4450 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2022-4450 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2022-4450. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
A double-free vulnerability was found in the OpenSSL library in the PEM_read_bio_ex() function and its wrappers. The flaw is triggered when the library parses a specially crafted PEM file constructed to have zero bytes of payload data. This edge case causes the function to return a failure code but also populate a…
| Product | Fixed in | Advisory |
|---|---|---|
| JBoss Core Services for RHEL 8 | jbcs-httpd24-openssl-1:1.1.1k-14.el8jbcs | RHSA-2023:3354 |
| Red Hat Enterprise Linux 8 | edk2-0:20220126gitbb1bba3d77-4.el8 | RHSA-2023:2932 |
| Red Hat Enterprise Linux 8 | openssl-1:1.1.1k-9.el8_7 | RHSA-2023:1405 |
| Red Hat Enterprise Linux 8.6 Extended Update Support | openssl-1:1.1.1k-9.el8_6 | RHSA-2023:3408 |
| Red Hat Enterprise Linux 9 | openssl-1:3.0.1-47.el9_1 | RHSA-2023:0946 |
| Red Hat Enterprise Linux 9 | edk2-0:20221207gitfff6d81270b5-9.el9_2 | RHSA-2023:2165 |
| Red Hat Enterprise Linux 9.0 Extended Update Support | openssl-1:3.0.1-46.el9_0 | RHSA-2023:1199 |
| Red Hat JBoss Web Server 5 | openssl | RHSA-2023:3421 |
Frequently Asked Questions
Is CVE-2022-4450 in your dependencies?
O3 Security finds CVE-2022-4450 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.