1. the Many-Faced Threats
to the serverless world

2. Yan Cui
http://theburningmonk.com
@theburningmonk
Principal Engineer @

3. “Netflix for sports”
offices in London, Leeds, Katowice and Tokyo

4. We’re hiring ;-)
http://engineering.dazn.com

5. AWS user since 2009

8. recording: https://www.youtube.com/watch?v=s4L5wjFlFzA
slides: http://bit.ly/2tHYFAM
blog posts: http://theburningmonk.com/yubls-road-to-serverless-architecture

9. Shared Responsibility Model

10. Shared Responsibility Model

11. protection from OS attacks
Amazon automatically apply latest patches to host VMs

14. still have to patch your code
vulnerable code, 3rd party dependencies, etc.

16. https://snyk.io/blog/owasp-top-10-breaches

17. https://snyk.io/blog/owasp-top-10-breaches
Known Vulnerable Components cause 24% of the top
50 data breaches in 2016

18. https://snyk.io/blog/77-percent-of-sites-use-vulnerable-js-libraries

23. http://bit.ly/2topw5I

24. sanitise inputs & outputs
(standardise and encapsulate into shared lib)

26. http://bit.ly/2gSHtay
Broken Access Control
Insecure Direct Object Reference
Information Leakage
GraphQL Injection

27. http://bit.ly/2uKhGXF

28. http://bit.ly/2uKhGXF

29. app dependency is a
large attack surface

30. further compounded by
transient dependencies

31. https://david-dm.org/request/request?view=tree

33. https://snyk.io

34. security updates are often
bundled with unrelated
feature and API changes

35. your security is as strong
as its weakest link

36. OS
Application
Dependencies
physical
infrastructure
NPM Authors
Container
runs in
runs in
runs in
has
hosted by published by
pushes to
Developers
develops uses
Users
guardsprotects
Networking
runs on
needs
Source Code
has
maintains

37. OS
Application
Dependencies
physical
infrastructure
NPM Authors
Container
runs in
runs in
runs in
has
hosted by published by
pushes to
Developers
develops uses
Users
guardsprotects
Networking
needs
runs on this is where an attacker will
target in a movie
Source Code
has
maintains

40. OS
Dependencies
physical
infrastructure
NPM Authors
Container
runs in
runs in
runs in
has
hosted by published by
pushes to
Developers
develops uses
Users
guardsprotects
Application
A9
Networking
runs on
needs
Source Code
has
maintains
A1, A3, …

41. people are often the WEAKEST link
in the security chain

43. OS
Dependencies
physical
infrastructure
NPM Authors
Container
runs in
runs in
runs in
has
hosted by published by
pushes to
Developers
develops uses
Users
guardsprotects
Application
phishing…
Networking
runs on
needs
Source Code
has
maintains

44. OS
Dependencies
physical
infrastructure
NPM Authors
Container
runs in
runs in
runs in
has
hosted by published by
pushes to
Developers
develops uses
Users
guardsprotects
Application
brute force, known
account leaks, …
Networking
runs on
needs
Source Code
has
maintains

45. OS
Dependencies
physical
infrastructure
NPM Authors
Container
runs in
runs in
runs in
has
hosted by published by
pushes to
Developers
develops uses
Users
guardsprotects
Application
brute force, known
account leaks, …
Networking
runs on
needs
Source Code
has
maintains

46. http://bit.ly/2sFDwYX
…obtained publish access to 14% of npm packages…

47. http://bit.ly/2sFDwYX
debug, request, react, co, express, moment, gulp, mongoose, mysql, bower,
browserify, electron, jasmine, cheerio, modernizr, redux, …

48. http://bit.ly/2sFDwYX
total downloads/month of the unique packages
which I got myself publish access to was 1 972 421
945, that's 20% of the total number of d/m directly.

49. 20% of all monthly NPM downloads…

50. brute force
known account leaks from other sources
leaked NPM credentials (github, etc.)

51. http://bit.ly/2sFDwYX

52. http://bit.ly/2sFDwYX
662 users had password “123456”
172 — “123”
124 — “password”

55. WTF!?!?

58. oh god, that was too easy…

61. compromised package is a
transient dependency
sigh…

62. still “works”…

65. npmjs.com/~hacktask

67. rm -rf / !!!

68. NPM default - get latest
“compatible” version, ie. 1.X.X

69. clean install (eg. on CI server) will
download the latest, compromised
package without any code change…
NPM default - get latest
“compatible” version, ie. 1.X.X

71. use npm shrinkwrap
or upgrade to NPM 5

72. imagine…

73. not specific to Node.js or NPM

75. Shared Responsibility Model

76. who can invoke the function?

77. what can the function access?

78. Least Privilege Principle

80. everything here
is trusted

82. always public
implement authentication with
API keys, Cognito, or custom
authorizer functions

83. compromised servers
allow attacker to access all
of your sensitive data!

84. implement authentication
for internal APIs

85. use AWS_IAM
authentication for
internal APIs

87. minimise function’s access

91. requires developer discipline

92. IAM policies not versioned
with Lambda functions

93. better in Serverless 1.X

94. AWS Lambda
docs
Write your Lambda function
code in a stateless style, and
ensure there is no affinity
between your code and the
underlying compute
infrastructure.
http://amzn.to/2jzLmkb

95. S3
AWS IoT
DynamoDB
RDS
EventStore
Elasticsearch Couchbase
Redshift
Neo4j
Google BigQuery

96. secure sensitive data both
at rest and in-transit

97. leverage server-side encryption

98. http://amzn.to/1N3Twb8

99. http://amzn.to/1xF41eX

100. http://amzn.to/2tgvFR2

101. Least Privilege Principle

102. Disposability is a virtue

103. AWS Lambda
docs
Delete old Lambda functions that
you are no longer using.
http://amzn.to/2jzLmkb

104. easier said than done…

105. identifying component
ownership in a big IT
organization is challenging

106. identifying ownership of
individual functions is
much harder

107. source: http://www.digitalattackmap.com

108. more likely to scale through
DoS attacks

109. DoS + per exec billing =
Denial of Wallet problem

110. have to choose between a
DoS and a DoW problem…

112. AWS Shield Advanced also gives you access to the AWS
DDoS Response Team (DRT) and protection against DDoS
related spikes in your ELB, CloudFront or Route 53 charges.

113. async sync
S3
SNS
SES
CloudFormation
CloudWatch Logs
CloudWatch Events
Scheduled Events
CodeCommit
AWS Config
http://amzn.to/2vs2lIg
Cognito
Alexa
Lex
API Gateway
streams
DynamoDB Stream
Kinesis Stream
Lambda handles retries
(twice, then DLQ)

114. http://bit.ly/2v7F2E4

115. DoS attack
2+ Retries+
?

116. DoS attack
Regex DoS attack
long Lambda timeout
2+ Retries+
?

118. Day 1

119. Day 2

121. no long-lived
compromised servers

122. containers are reused, avoid
sensitive data in /tmp

126. no accidentally exposed
directories

130. http://bit.ly/2tlGTbc

131. monitor activities in
unused regions using
CloudWatch Events

133. set up billing alarms in
unused regions

134. watertight compartments that can contain water in
the case of hull breach or other leaks

135. Michael Nygard

137. least privilege principle

138. per function policies

139. account level isolation

140. Recap

141. App dependencies is a much BIGGER attack
surface than you probably realise

143. sanitise inputs and outputs

144. Least Privilege Principle

145. here’s your per function policy
NEXT!

146. S3
AWS IoT
DynamoDB
RDS
EventStore
Elasticsearch Couchbase
Redshift
Neo4j
Google BigQuery
encrypt data at rest

147. S3
AWS IoT
DynamoDB
RDS
EventStore
Elasticsearch Couchbase
Redshift
Neo4j
Google BigQuery
and in-transit

148. delete unused functions.

149. DoS DoW*
* Denial of Wallet

153. no server*
no OS attacks
no long lived compromised servers
* I know I know, there’s still a server somewhere, but it’s managed and secured by AWS engineers who can do a much better
job of it than most of us can; and the servers are ephemeral and short-lived

154. don’t be an unwilling bit miner

155. don’t be an unwilling bit miner
safeguard your credentials…

156. prod dev
compartmentalise breaches

157. people are often the WEAKEST link
in the security chain

158. @theburningmonk
theburningmonk.com
github.com/theburningmonk