# CASCA evidence receipt — CVE-2017-1000253

- Generation: `gen-56ccdaf914f7b4be95b689ccae7dc20d`
- As known: 2026-07-19T05:00:42+00:00
- Comparison: first_public_core_generation
- Score policy: public-priority-v1.0.1
- Conflict: not observed in this generation

## Source assertions

- **CISA-ADP** (independent_enrichment): container — CISA ADP Vulnrichment
  - Observed: 2026-07-19T04:27:06.398189+00:00
  - Citation: https://www.cve.org/CVERecord?id=CVE-2017-1000253
- **CVE** (derivative_copy): container — CVE Program Container
  - Observed: 2026-07-19T04:27:06.398189+00:00
  - Citation: https://www.cve.org/CVERecord?id=CVE-2017-1000253
- **mitre** (original_assertion): container — Linux distributions that have not patched their long-term kernels with https://git.kernel.org/linus/a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (committed on April 14, 2015). This kernel vulnerability was fixed in April 2015 by commit a87938b2e246b81b4fb713edb371a9fa3c5c3c86 (backported to Linux 3.10.77 in May 2015), but it was not recognized as a security threat. With CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE enabled, and a normal top-down address allocation strategy, load_elf_binary() will attempt to map a PIE binary into an address range immediately below mm->mmap_base. Unfortunately, load_elf_ binary() does not take account of the need to allocate sufficient space for the entire binary which means that, while the first PT_LOAD segment is mapped below mm->mmap_base, the subsequent PT_LOAD segment(s) end up being mapped above mm->mmap_base into the are that is supposed to be the "gap" between the stack and the binary.
  - Observed: 2026-07-19T04:27:06.398189+00:00
  - Citation: https://www.cve.org/CVERecord?id=CVE-2017-1000253
- **CISA KEV** (original_assertion): observed_exploitation — Linux Kernel PIE Stack Buffer Corruption Vulnerability 
  - Observed: 2026-07-19T04:54:04.25158+00:00
  - Citation: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- **FIRST EPSS** (original_assertion): model_probability — Probability 0.106950000000; percentile 0.953200000000
  - Observed: 2026-07-19T04:54:35.756809+00:00
  - Citation: https://www.first.org/epss/data_stats.html

## CVSS assessments

- **nvd@nist.gov** (Primary, CVSS 3.1): 7.8 — score eligible
  - Evidence class: nvd_enrichment_exact; source rank: 0
  - Validation: valid_match
  - Vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
- **nvd@nist.gov** (Primary, CVSS 2.0): 7.2 — score eligible
  - Evidence class: nvd_enrichment_exact; source rank: 0
  - Validation: valid_match
  - Vector: `AV:L/AC:L/Au:N/C:C/I:C/A:C`
- **134c704f-9b21-4f2e-91b3-4a467353bcc0** (Secondary, CVSS 3.1): 7.8 — score eligible
  - Evidence class: registered_adp_or_other; source rank: 2
  - Validation: valid_match
  - Vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
- **CISA-ADP** (unknown, CVSS 3.1): 7.8 — display only
  - Evidence class: direct_cve_record_display_only; source rank: not applicable
  - Validation: display-only direct record assessment
  - Vector: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`

## Limitations and unknowns

- KEV membership is authoritative for the catalog, not proof of exposure in any environment.
- EPSS is a dated model probability and not an individual-environment prediction.
- Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
- NVD-carried upstream facts remain derivative and are not independent corroboration.
- Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
- NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
- Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
- Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.

Generated from CASCA normalized evidence. This receipt is not proof that an asset is affected, unaffected, safe, or fixed.