Security readout for executives and security teams
Plain-English summary
A flaw in Python’s archive extraction protections can let a malicious tar archive create links pointing outside the intended destination and alter some file metadata. This could allow unauthorized file changes under the extracting process’s permissions. Risk is concentrated in systems that automatically accept and unpack untrusted archives.
Executive priority
Treat as a high-priority integrity issue where customers, partners, or automated feeds can supply tar archives. Prioritize internet-facing upload workflows and privileged extraction services. Accelerate remediation if extraction can reach application files, configuration, deployment assets, or shared storage; otherwise schedule prompt patching after confirming actual tarfile use.
Technical view
CVE-2025-4330 is a CWE-22 path-control flaw in CPython’s tarfile module. The "data" and "tar" extraction filters can be bypassed through link targets outside the extraction directory. Affected usage includes TarFile.extractall() or TarFile.extract() with those filters, plus Python 3.14 users relying on the new default "data" filter.
Likely exposure
Exposure requires affected CPython code to extract attacker-controlled or otherwise untrusted tar archives. Upload processors, conversion services, build systems, and automation pipelines warrant review. Systems that never extract untrusted archives through tarfile are less likely exposed. The supplied affected-version data is incomplete, so confirm exact versions through vendor guidance.
Exploitation context
The CVSS 3.1 score is 7.5, reflecting remotely supplied input, low complexity, no privileges, no user interaction, and high integrity impact. The source bundle marks this CVE as absent from KEV and provides no evidence of active exploitation. Network reachability depends on how an application obtains archives; tarfile itself is not necessarily network-facing.
Researcher notes
The reported behavior concerns extraction-filter enforcement for link destinations and some metadata changes. The source bundle lists CPython branches beginning with 3.10 through 3.14 alpha, but does not clearly express complete affected ranges or fixed release numbers. Review branch-specific commits and the Python security advisory before making precise version determinations. Source-distribution installation already permits build-time code execution, limiting this CVE’s incremental impact there.
Mitigation direction
- Apply the vendor-provided CPython fix for the installed supported branch.
- Pause or isolate extraction of untrusted tar archives until affected runtimes are remediated.
- Follow the vendor-linked mitigation guidance where immediate patching is unavailable.
- Run extraction with minimal filesystem permissions and segregate destination storage.
Validation and detection
- Inventory CPython versions in applications, containers, build workers, and automation hosts.
- Find TarFile.extractall() and TarFile.extract() calls, including wrappers and indirect library usage.
- Identify calls using "data", "tar", or Python 3.14 default filtering with untrusted archives.
- Confirm installed packages contain the applicable vendor patch using trusted package provenance.
- Regression-test that archive links cannot affect paths outside an isolated extraction directory.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-22: File access and web shell behavior lookup
File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2025-4330 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N3.93.6PSFVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/python/cpython/issues/135034CVE reference, PSF · issue-tracking
- https://github.com/python/cpython/pull/135037CVE reference, PSF · patch
- https://mail.python.org/archives/list/security-announce@python.org/thread/MAXIJJCUUMCL7ATZNDVEGGHUMQMUUKLG/CVE reference, PSF · vendor-advisory
- https://github.com/python/cpython/commit/3612d8f51741b11f36f8fb0494d79086bac9390aCVE reference, PSF · patch
- https://github.com/python/cpython/commit/9e0ac76d96cf80b49055f6d6b9a6763fb9215c2aCVE reference, PSF · patch
- https://gist.github.com/sethmlarson/52398e33eff261329a0180ac1d54f42fCVE reference, PSF · mitigation
- https://github.com/python/cpython/commit/19de092debb3d7e832e5672cc2f7b788d35951daCVE reference, PSF · patch
- https://github.com/python/cpython/commit/aa9eb5f757ceff461e6e996f12c89e5d9b583b01CVE reference, PSF · patch
- https://github.com/python/cpython/commit/28463dba112af719df1e8b0391c46787ad756dd9CVE reference, PSF · patch
- https://github.com/python/cpython/commit/4633f3f497b1ff70e4a35b6fe2c907cbe2d4cb2eCVE reference, PSF · patch
- https://github.com/python/cpython/commit/9c1110ef6652687d7c55f590f909720eddde965aCVE reference, PSF · patch
- https://github.com/python/cpython/commit/dd8f187d0746da151e0025c51680979ac5b4cfb1CVE reference, PSF · patch
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.