SSRFとmetadata

2018/01/19に行われたJAWS-UG沖縄の登壇資料です。
https://jaws-ug-okinawa.doorkeeper.jp/events/85333

Transcript

1. SSRFͱmetadata JAWS-UGԭೄ
 2018.01.19
 Core Member YUYA ASATO 
 @328__
2. ࣗݾ঺հ • Name : ҆ཬ ༔໼
 Twitter : @328__
 JAWS-UGԭೄ ίΞϝϯόʔ • ීஈ͸ηΩϡϦςΟͳ
 ͓࢓ࣄΛͯ͠·͢
3. AWSͷ੹೚ڞ༗Ϟσϧ https://aws.amazon.com/jp/compliance/shared-responsibility-model/
4. IAM ϩʔϧ࢖ͬͯ·͔͢ʁ
5. IAM
 (Identity and Access Management) AWSαʔϏεͷૢ࡞ΛΑΓηΩϡΞʹߦ͏ͨΊͷ
 ೝূɾೝՄͷ࢓૊Έ *".
   Ϣʔβ *".
   ϩʔϧ - ϚωδϝϯτίϯιʔϧͷϩάΠϯ - ར༻ऀ(User)୯ҐͰ࡞੒ - αʔϏε୯ҐͰAWSૢ࡞ݖݶΛ෇༩
6. IAMϩʔϧΛ࢖͏ϝϦοτ • IAMϢʔβΑΓ΋ೝূ৘ใͷ؅ཧָ͕ • ೝূ৘ใͷࣗಈߋ৽͕Մೳ • ΞϓϦέʔγϣϯ΁ͷϋʔυίʔσΟϯά๷ࢭ
7. IAMϩʔϧͱmetadata • ԼهͷURLʹcredentials͕ଘࡏ
 http://169.254.169.254/latest/meta-data/iam/security- credentials/ • ͜͜ʹcredentials͕ೖ͍ͬͯΔͷͰAWS CLI ΍AWS SDK͕ར༻Ͱ͖Δ metadataΛಡΈࠐΉ͜ͱͰ
 AWSϦιʔε΁ͷΞΫηε͕Մೳ https://docs.aws.amazon.com/ja_jp/AWSEC2/latest/UserGuide/ec2-instance-metadata.html
8. IAM Roleͷར༻ = ҆શʁ • ೝূ৘ใΛਓ͕ؒ؅ཧ͠ͳ͍෼ʹ͸҆શ • ֎෦͔ΒmetadataʹΞΫηεͰ͖ͯ͠·͑͹ ೝূ৘ใΛ઄औ͢Δ͜ͱ͸Մೳ
9. SSRF
 (Server Side Request Forgery) • ߈ܸऀ͔Β௚઀౸ୡͰ͖ͳ͍αʔόʹ
 ର͢Δ߈ܸख๏
10. SSRFΛར༻ͨ͠ೝূ৘ใͷऔಘ demo
11. ରࡦ • Ͱ͖Δ͜ͱͳΒϢʔβ͔ΒURL,ύεͷೖྗΛड͚෇͚ͳ͍ • ڐՄ͞ΕͨURLͷҰཡදʢϗϫΠτϦετʣΛ࡞੒ͯ͠Ξ ΫηεͰ͖ΔൣғΛݶఆ͢Δ • Ϩεϙϯεͷݕূͱ͔΋΍ͬͨ΄͏͕͍͍ʁ • IAMϩʔϧʹ෇༩͢ΔݖݶΛ࠷খԽ
 AdministratorAccessͱ͔౉ͪ͠Όμϝ…
12. ରࡦͷ೉͠͞ • αʔϏεͰAWSSDK࢖ͬͯͨΓ͢Δͱ
 firewalldͰϒϩοΫͰ͖ͳ͍ • ೖྗ஋ΛϑΟϧλ͢Δͷ΋ͳ͔ͳ͔೉͍͠
 8ਐ਺, 16ਐ਺ͷࠞࡏදه΋Ͱ͖Δ
 http://0xA9FEA9FE
 http://0xA9.0xFE.0xA9.0xFE
 http://0251.0376.0251.0376
 http://0xA9.0376.0251.0xFE
13. ࡶײ • WebΞϓϦέʔγϣϯʹ੬ऑੑ͕͋Ε͹
 AWSͷೝূ৘ใΛ֎෦͔ΒऔಘͰ͖Δ • ೖྗ஋ͷݕূͬͯ೉͍͠….