컨테이너 이미지 취약점 스캔 결과 읽는 법 — Critical 수백 개를 0으로 만드는 실제 방법

trivy image --scanners vuln registry.acme.com/payments:1.4.2

registry.acme.com/payments:1.4.2 (debian 12.6)
Total: 1247 (UNKNOWN: 0, LOW: 812, MEDIUM: 289, HIGH: 137, CRITICAL: 9)

node-pkg (node-pkg)
Total: 6 (UNKNOWN: 0, LOW: 0, MEDIUM: 4, HIGH: 2, CRITICAL: 0)

trivy image --list-all-pkgs --format json node:22 \
  | jq '[.Results[].Packages // [] | length] | add'

432

trivy image --format json node:22 \
  | jq -r '.Results[].Vulnerabilities[]? | [.PkgName, .InstalledVersion, .VulnerabilityID, .Severity] | @tsv' \
  | head -5

libssl3   3.0.14-1~deb12u2   CVE-2024-5535   CRITICAL
libc6     2.36-9+deb12u8     CVE-2025-0395   MEDIUM
perl-base 5.36.0-7+deb12u1   CVE-2023-31486  HIGH
zlib1g    1:1.2.13.dfsg-1    CVE-2023-45853  CRITICAL
tar       1.34+dfsg-1.2      CVE-2005-2541   HIGH

docker run --rm debian:12-slim bash -lc 'dpkg -l | grep -E "^ii\s+openssl"'

ii  openssl  3.0.14-1~deb12u2  amd64  Secure Sockets Layer toolkit

docker run --rm debian:12-slim bash -lc \
  'apt-get -qq update && apt-get -qq changelog openssl 2>/dev/null | head -12'

openssl (3.0.14-1~deb12u2) bookworm-security; urgency=medium

  * Fix CVE-2024-5535: SSL_select_next_proto buffer overread
  * Fix CVE-2024-4741: use-after-free in SSL_free_buffers

 -- Debian Security Team  Mon, 08 Jul 2026 21:14:02 +0000

trivy image --format json debian:12-slim \
  | jq -r '.Results[].Vulnerabilities[]? | .Status' | sort | uniq -c | sort -rn

     58 will_not_fix
     23 affected
      6 fixed
      2 end_of_life

trivy image --ignore-unfixed --severity CRITICAL,HIGH registry.acme.com/payments:1.4.2

Total: 4 (HIGH: 3, CRITICAL: 1)

trivy image --scanners vuln,secret,misconfig registry.acme.com/payments:1.4.2

payments:1.4.2 (secrets)
HIGH: AWS Access Key ID
 Dockerfile:22
   ENV AWS_ACCESS_KEY_ID=AKIA****************

payments:1.4.2 (dockerfile)
HIGH: DS002 Image user should not be root
   Specify at least 1 USER command with non-root user

RUN curl -fsSL https://example.com/tools/legacy-cli-1.2.0.tar.gz \
  | tar xz -C /usr/local/bin

# 프로세스가 실제로 열고 있는 공유 라이브러리
docker run --rm --entrypoint sh registry.acme.com/payments:1.4.2 -c \
  'ldd /usr/local/bin/node | awk "{print \$1}" | sort'

libc.so.6
libcrypto.so.3
libdl.so.2
libgcc_s.so.1
libm.so.6
libpthread.so.0
libssl.so.3
libstdc++.so.6

curl -s 'https://api.first.org/data/v1/epss?cve=CVE-2021-44228,CVE-2023-45853,CVE-2024-5535' \
  | jq -r '.data[] | [.cve, .epss, .percentile] | @tsv'

CVE-2021-44228  0.944400  0.99970
CVE-2023-45853  0.004120  0.74331
CVE-2024-5535   0.001960  0.58207

curl -s https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json \
  | jq -r '.vulnerabilities[].cveID' | sort -u > /tmp/kev.txt

trivy image --format json registry.acme.com/payments:1.4.2 \
  | jq -r '.Results[].Vulnerabilities[]?.VulnerabilityID' | sort -u > /tmp/found.txt

comm -12 /tmp/found.txt /tmp/kev.txt

CVE-2023-38545

# syntax=docker/dockerfile:1

FROM node:22 AS build
WORKDIR /app
COPY package.json package-lock.json ./
RUN npm ci --ignore-scripts
COPY . .
RUN npm run build && npm prune --omit=dev

FROM gcr.io/distroless/nodejs22-debian12:nonroot
WORKDIR /app
COPY --from=build --chown=nonroot:nonroot /app/node_modules ./node_modules
COPY --from=build --chown=nonroot:nonroot /app/dist ./dist
USER nonroot
EXPOSE 8080
CMD ["dist/server.js"]

trivy image --ignore-unfixed --severity CRITICAL,HIGH registry.acme.com/payments:1.4.2
trivy image --ignore-unfixed --severity CRITICAL,HIGH registry.acme.com/payments:1.5.0

payments:1.4.2 (debian 12.6)
Total: 4 (HIGH: 3, CRITICAL: 1)

payments:1.5.0 (debian 12.6)
Total: 0 (HIGH: 0, CRITICAL: 0)

payments:1.5.0 (node-pkg)
Total: 2 (HIGH: 2, CRITICAL: 0)

kubectl debug -it pod/payments-7d9f -c debugger --image=busybox --target=app

trivy image \
  --scanners vuln \
  --severity CRITICAL,HIGH \
  --ignore-unfixed \
  --ignorefile .trivyignore.yaml \
  --exit-code 1 \
  registry.acme.com/payments:1.5.0

if comm -12 /tmp/found.txt /tmp/kev.txt | grep -q .; then
  echo "KEV 목록에 포함된 취약점이 있습니다. 배포를 중단합니다."
  comm -12 /tmp/found.txt /tmp/kev.txt
  exit 1
fi

# .trivyignore.yaml
vulnerabilities:
  - id: CVE-2024-45491
    paths:
      - usr/lib/x86_64-linux-gnu/libexpat.so.1.8.10
    statement: 이 서비스는 신뢰되지 않은 XML을 파싱하지 않음. 8월 베이스 이미지 교체로 해소 예정.
    expired_at: 2026-09-30

  - id: CVE-2023-45853
    statement: zlib은 정적 링크되지 않으며 호출 경로 없음. 데비안 will_not_fix 판정.
    expired_at: 2026-10-31

python3 - <<'PY'
import datetime, yaml
data = yaml.safe_load(open(".trivyignore.yaml"))
today = datetime.date.today()
for v in data.get("vulnerabilities", []):
    due = v["expired_at"]
    left = (due - today).days
    if left < 30:
        print(f"{v['id']}  만료 {left}일 남음  {v['statement'][:40]}")
PY

cosign sign --yes registry.acme.com/payments:1.5.0
cosign attest --yes --type cyclonedx --predicate sbom.cdx.json registry.acme.com/payments:1.5.0

apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: verify-image-signature
spec:
  validationFailureAction: Enforce
  rules:
    - name: check-signature
      match:
        any:
          - resources:
              kinds:
                - Pod
      verifyImages:
        - imageReferences:
            - registry.acme.com/*
          attestors:
            - entries:
                - keyless:
                    subject: https://github.com/acme/payments/.github/workflows/release.yaml@refs/heads/main
                    issuer: https://token.actions.githubusercontent.com