Use-After-Free in openexr (CVE-2025-64183)
Summary
Vulnerability in openexr (CVE-2025-64183). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 3.4.3 or later.
Original description
The description as published by the source.
Summary
There is a use-after-free in PyObject_StealAttrString of pyOpenEXR_old.cpp.
This bug was found with ZeroPath.
Details
The legacy adapter defines PyObject_StealAttrString that calls PyObject_GetAttrString to obtain a new reference, immediately decrefs it, and returns the pointer. Callers then pass this dangling pointer to APIs like PyLong_AsLong/PyFloat_AsDouble, resulting in a use-after-free. This is invoked in multiple places (e.g., reading PixelType.v, Box2i, V2f, etc.).
PoC
import OpenEXR, Imath
# Any small EXR will do - use one from OpenEXR test images or any project file
path = "any_small.exr"
# Property returns a fresh temporary int subclass, so the buggy helper
# decrefs it to zero before passing it to PyLong_AsLong => UAF.
class FreshInt(int):
def __new__(cls, v):
return int.__new__(cls, v)
def __del__(self):
# stir the heap to make the UAF obvious under PYTHONMALLOC=debug
_ = bytearray(1_000_000)
class PixelTypeProxy:…
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2025-64183 has been found in openexr.
Risk of unauthorized operations or information disclosure.
What to do: upgrade openexr to 3.4.3 or later.
If unsure, ask your IT team or search "openexr CVE-2025-64183" on the vendor's site.
CVE-2025-64183 (openexr) — CWE-416
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 3.4.3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Use-after-free (CWE-416) exists in openexr.
Check the vendor advisory for the affected versions of openexr.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 3.4.3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'openexr' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'openexr' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
openexrを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade openexr to 3.4.3ステージング環境で 3.4.3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com