Is nltk safe?
- Python shell/command execution
- Python dynamic code execution
- Unsafe deserialization
nltk-3.10.3 is an AI python_package analyzed by SkillTotal's deterministic static scanner. The scan found no malicious indicators, though 6 risky constructs are reported for review. It can: dynamic code execution, filesystem read, filesystem write, network egress and shell execution — capabilities are what the code can do, not a verdict on intent. Risk score 20/100 (low).
nltk-3.10.3 3.10.3
Automated static-analysis result. It can contain false positives and false negatives, and is not a claim about the intent of nltk's authors. Report a false positive.
Behavioral traits
How this component maps to the CSA agentic threat model. Descriptive — it never affects the risk score.
Findings (6)
It loads data with a format that can rebuild arbitrary objects (e.g. pickle, or unsafe YAML).
db_out = shelve.open(db, "n")
db_in = shelve.open(db)
Why it matters: Feeding such a loader untrusted data can execute code hidden inside that data.
Fix: Deserialize untrusted data with a safe format/loader: JSON, or yaml.safe_load / Loader=SafeLoader. Reserve pickle/marshal for data you fully control.
The code turns strings into live code at runtime (eval / new Function / exec).
funcopy = eval(src, dict(_wrapper_=wrapper))
dec_func = eval(src, dict(_func_=func, _call_=caller))
return eval(s[start_position : match.end()]), match.end()
w = eval("numpy." + window + "(window_len)")Why it matters: If those strings aren't fixed and trusted, they become a way to run arbitrary code.
Fix: Avoid evaluating dynamically constructed code; if unavoidable, ensure the input is a trusted constant and never derived from external data.
The component can run operating-system commands or spawn processes.
p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
p = Popen(_senna_cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
p = subprocess.Popen(cmd, stdout=sys.stdout)
p = subprocess.Popen(
["svn", "status", "-v", filename],
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
)p = subprocess.Popen(
cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, stdin=subprocess.PIPE
)p = subprocess.Popen(
final_cmd,
stdin=stdin,
stdout=stdout,
stderr=stderr,
universal_newlines=True,
)p = subprocess.Popen(
["which", alternative],
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
)proc = subprocess.run(
[dot_binary, "-T%s" % t],
capture_output=True,
input=dot_string,
text=True,
)proc = subprocess.run(
[dot_binary, "-T%s" % t],
input=bytes(dot_string, encoding="utf8"),
)p = subprocess.Popen(cmd, stdout=output, stderr=output, cwd=cwd)
p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
p = subprocess.Popen(
cmd,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
)self._hunpos = Popen(
[self._hunpos_bin, self._hunpos_model],
shell=False,
stdin=PIPE,
stdout=PIPE,
stderr=PIPE,
)p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
process = subprocess.Popen(
[dot_binary, "-T%s" % output_format],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
)Why it matters: Powerful and often legitimate — confirm the commands aren't built from untrusted input.
Fix: Confirm the command and its arguments are fully controlled and not derived from untrusted input; avoid shell=True.
The component reads files from disk.
with open(version_file) as infile:
with open(filename, "rb") as infile:
with open(filename, "rb") as infile:
with open(filename, "rb") as infile:
with open(filename) as infile:
with open(filename) as infile:
with open(usp) as infile:
"text": _ieer_read_text(m.group("text"), root_label),"headline": _ieer_read_text(m.group("headline"), root_label),return _ieer_read_text(s, root_label)
with open(weightfile_name) as weightfile:
with self.abspath(framefile).open() as fp:
with self.abspath(framefile).open() as fp:
with self.abspath(framefile).open() as fp:
with self.abspath(framefile).open() as fp:
with self.abspath(fileid).open() as fp:
return find(path_).open()
return find(local_path).open()
with open(file, "rb") as infile:
with open(file, "rb") as infile:
with open(options.file) as infile:
with open(output_file_name) as infile:
with open(modelFile, "rb") as f:
with open(path) as fin:
with open(cache_baseline_tagger, "rb") as print_rules:
Why it matters: Usually legitimate, but worth confirming it can't be steered into reading sensitive files.
Fix: Confirm which files are read and that paths cannot be influenced by untrusted input to reach sensitive locations.
The component writes or deletes files on disk.
with open(filename, "wb") as outfile:
with open(filename, "wb") as outfile:
with open(filename, "wb") as outfile:
with open(filename, "w") as outfile:
with open(filename, "w") as outfile:
with open(filename, "w") as outfile:
logfile = open(logfilename, "a", 1) # 1 means 'line buffering'
with open(trainfile_name, "w") as trainfile:
os.remove(trainfile_name)
os.remove(trainfile_name)
os.remove(weightfile_name)
with open(f"{tab_dir}/weights.txt", "w") as f:with open(f"{tab_dir}/mapping.tab", "w") as f:with open(f"{tab_dir}/labels.txt", "w") as f:with open(f"{tab_dir}/alwayson.tab", "w") as f:os.remove(os.path.join(temp_dir, f))
os.remove(os.path.join(temp_dir, f))
outfile = open(outfile, "w")
os.remove(self.write_file.name)
os.remove(path)
os.remove(os.path.join(root, name))
with open(filename, "wb") as f:
os.remove(filename)
os.remove(input_file.name)
os.unlink(input_file_name)
Why it matters: Usually legitimate, but worth confirming the paths can't be controlled by untrusted input.
Fix: Confirm which files are written/deleted and that paths cannot be influenced by untrusted input.
The component makes outbound network requests.
import urllib.request
from urllib.request import url2pathname
p = os.path.join(path_, url2pathname(resource_name))
pkg_dir = os.path.join(path_, url2pathname(pkg))
pkg_zip = os.path.join(path_, url2pathname(pkg + ".zip"))
p = os.path.join(path_, url2pathname(zipfile))
local_path = url2pathname(path_)
import requests
response = requests.get(requests.compat.urljoin(self.url, "live"))
response = requests.get(requests.compat.urljoin(self.url, "ready"))
import requests
self.session = requests.Session()
import http.client
import urllib.request
handlers.append(urllib.request.ProxyHandler(isolated_proxies))
handlers.append(urllib.request.ProxyBasicAuthHandler(handler.passwd))
handlers.append(urllib.request.ProxyDigestAuthHandler(handler.passwd))
if not proxied and not has_proxy_handler and urllib.request.getproxies():
handlers.append(urllib.request.ProxyHandler({}))opener = urllib.request.build_opener(*handlers)
import requests
from urllib.request import (
HTTPPasswordMgrWithDefaultRealm,
ProxyBasicAuthHandler,
ProxyDigestAuthHandler,
ProxyHandler,
build_opener,
getproxies,
install_opener,
)proxy = getproxies()["http"]
proxy_handler = ProxyHandler({"https": proxy, "http": proxy})opener = build_opener(proxy_handler)
Why it matters: Usually legitimate, but confirm the destinations are expected and no sensitive data leaves.
Fix: Confirm the destination hosts are expected and that no sensitive data is sent off-host.
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