GHSA-gqr6-r77p-c2pj: High severity maven/org.graylog2:graylog2-server vulnerability
Impact
A security issue has been identified in Graylog affecting the parsing of syslog messages that use a key-value format, such as those generated by Fortigate devices.
The vulnerability allows attackers to overwrite individual message fields, or to produce invalid messages which Graylog will discard. This effectively enables log evasion techniques to obscure malicious activity.
Patches
The issue has been fixed in the following Graylog versions: 6.3.12, 7.0.7, 7.1.2. Users should upgrade to one of these versions or above to remediate the vulnerability.
Graylog Cloud has already been patched.
Workarounds
There are no feasible workarounds for this issue. Upgrading to a patched version is recommended.
To find potentially discarded messages due to parsing errors, customers of Graylog Enterprise or Security can check the Indexing and Processing Failures Index[^1].
Credits
Thanks to Jose Luis González, from Fundación Sarenet, with additional analysis by Borja Marcos from Sarenet.
[^1]: https://go2docs.graylog.org/current/gettinginlogdata/indexerandprocessingfailures.html
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
maven/org.graylog2:graylog2-serverto a version that resolves this vulnerability.Fixed in 7.1.2 - Upgrade
Upgrade
maven/org.graylog2:graylog2-serverto a version that resolves this vulnerability.Fixed in 7.0.7 - Upgrade
Upgrade
maven/org.graylog2:graylog2-serverto a version that resolves this vulnerability.Fixed in 6.3.12 - Upgrade
Upgrade
Graylogto a version that resolves this vulnerability.Fixed in 6.3.12 - Upgrade
Upgrade
Graylogto a version that resolves this vulnerability.Fixed in 7.0.7 - Upgrade
Upgrade
Graylogto a version that resolves this vulnerability.Fixed in 7.1.2 - Compensating control
For Graylog Enterprise or Security customers, check the "Indexing and Processing Failures" Index for potentially discarded messages due to parsing errors.
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Graylog deployments that parse syslog messages in key-value format are affected, including messages such as those generated by Fortigate devices. Graylog Cloud has already been patched.
What would an attacker need to exploit it?
An attacker needs to be able to supply crafted key-value-format syslog messages to Graylog. The issue can be used to overwrite individual message fields or cause invalid messages to be discarded, enabling log evasion.
Which versions remediate the issue?
Upgrade Graylog to version 6.3.12, 7.0.7, 7.1.2, or a later version.
What can be done if an upgrade cannot happen immediately?
No feasible workaround is available. For Graylog Enterprise or Security customers, review the Indexing and Processing Failures Index for messages potentially discarded because of parsing errors.