GHSA-3h9h-qfvw-98hq — openexr
HIGHGHSA-3h9h-qfvw-98hq is a high-severity (CVSS 7.5) CWE-457 vulnerability in openexr. A fix is available for openexr — see the affected versions and patch details below.
OpenEXR Makes Use of Uninitialized Memory
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-3h9h-qfvw-98hq.
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
GHSA-3h9h-qfvw-98hq 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 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
openexr🐍openexrReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
While fuzzing openexr_exrcheck_fuzzer, Valgrind reports a conditional branch depending on uninitialized data inside generic_unpack. This indicates a use of uninitialized memory (CWE-457). The issue is reproducible with the current OSS-Fuzz harness and a single-file PoC.
Details
Environment:
- Tooling:
valgrind --tool=memcheck --track-origins=yes - Target:
openexr_exrcheck_fuzzer - OS: Ubuntu 20.04.6 LTS focal x86_64
- openexr version and Git-commit hash:
openexr 3.4.2 | commit fd657e8a41e157e5841c7cc2e2a5efe094b069a1 (grafted, HEAD -> main, origin/main, origin/HEAD)
Function: generic_unpack
Possible root cause (based on observed symptoms): The unpacker is branching on bytes in a scratch buffer that were never written because the decode step didn’t fully populate it.
- The first use flagged is in
generic_unpack(). That function reads from the decompressed/expanded pixel buffer to scatter data into the framebuffer. A “conditional jump depends on uninitialised value(s)” means it’s consulting bytes in that buffer before they were written. - Valgrind says the uninitialised value “was created by a heap allocation (malloc)”, not the stack: this matches a per-tile/per-scanline decode scratch buffer allocated in
exr_decoding_run().
Valgrind Trace (top frames):
==454== Conditional jump or move depends on uninitialised value(s)
==454== at 0x4539BE: generic_unpack (in /out/openexr_exrcheck_fuzzer)
==454== by 0x44B85F: exr_decoding_run (in /out/openexr_exrcheck_fuzzer)
==454== by 0x38BC5F: Imf_4_0::(anonymous namespace)::TileProcess::run_decode(_priv_exr_context_t const*, int, Imf_4_0::FrameBuffer const*, std::__1::vector<Imf_4_0::Slice, std::__1::allocator<Imf_4_0::Slice> > const&) (in /out/openexr_exrcheck_fuzzer)
==454== by 0x388BE1: Imf_4_0::TiledInputFile::Data::readTiles(int, int, int, int, int, int) (in /out/openexr_exrcheck_fuzzer)
==454== by 0x388619: Imf_4_0::TiledInputFile::readTiles(int, int, int, int, int, int) (in /out/openexr_exrcheck_fuzzer)
==454== by 0x353755: Imf_4_0::InputFile::Data::bufferedReadPixels(int, int) (in /out/openexr_exrcheck_fuzzer)
==454== by 0x352286: Imf_4_0::InputFile::readPixels(int) (in /out/openexr_exrcheck_fuzzer)
==454== by 0x3190FA: Imf_4_0::(anonymous namespace)::readMultiPart(Imf_4_0::MultiPartInputFile&, bool, bool) (in /out/openexr_exrcheck_fuzzer)
==454== by 0x314C4D: Imf_4_0::checkOpenEXRFile(char const*, unsigned long, bool, bool, bool) (in /out/openexr_exrcheck_fuzzer)
==454== Uninitialised value was created by a heap allocation at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
PoC
In the attached archive, you will find:
- The executable used for our tests.
- The testcase used to trigger the bug.
To observe the bug, simply run the OSS-Fuzz helper script:
git clone https://github.com/google/oss-fuzz.git
cd oss-fuzz
python3 infra/helper.py build_image openexr
python3 infra/helper.py build_fuzzers --sanitizer=none openexr
python3 infra/helper.py shell openexr
apt update && apt install -y valgrind
ulimit -n 65535
valgrind --tool=memcheck --track-origins=yes /out/openexr_exrcheck_fuzzer /path/to/poc
Impact
- Undefined Behavior
- Potential crash
- Denial of Service
Credit: Aldo Ristori archive0.zip
Update Note:
Other saved testcases from the fuzzing campaign trigger the same underlying bug, but with a different manifestation. So there is one root cause (missing post-decode validation / zero-init before any unpack), with different call-sites. Below there are several archives, formatted like the previous one, that reproduce the other test cases.
Other observed sinks (distinct manifestations of the same bug):
Deep pointers path: generic_unpack_deep_pointers (deep scanline/tiled) archive1.zip
Deep sample table path: unpack_sample_table (deep scanline) archive2.zip
Half conversion path: half_to_float_buffer_f16c via unpack_half_to_float_3chan_planar archive3.zip
Deep compositing: CompositeDeepScanLine::readPixels → ThreadPool::addTask → LineCompositeTask::execute archive4.zip
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | openexr | ≥ 3.3.0&&< 3.3.6 | 3.3.6pip install --upgrade 'openexr==3.3.6' |
| 🐍PyPI | openexr | ≥ 3.4.0&&< 3.4.3 | 3.4.3pip install --upgrade 'openexr==3.4.3' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openexr, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openexr to 3.3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3h9h-qfvw-98hq 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 GHSA-3h9h-qfvw-98hq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-3h9h-qfvw-98hq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-3h9h-qfvw-98hq in your dependencies?
O3 Security finds GHSA-3h9h-qfvw-98hq across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.