Impact
The power level parsing within gomatrixserverlib was failing to parse the "events_default" key of the m.room.power_levels event, defaulting the event default power level to zero in all cases.
In rooms where the "events_default" power level had been changed, this could result in events either being incorrectly authorised or rejected by Dendrite servers.
Patches
gomatrixserverlib contains a fix as of commit 723fd49 and Dendrite 0.9.3 has been updated accordingly.
Workarounds
Matrix rooms where the "events_default" power level has not been changed from the default of zero are not vulnerable.
For more information
If you have any questions or comments about this advisory, e-mail us at security@matrix.org.
Impact
The power level parsing within gomatrixserverlib was failing to parse the
"events_default"key of them.room.power_levelsevent, defaulting the event default power level to zero in all cases.In rooms where the
"events_default"power level had been changed, this could result in events either being incorrectly authorised or rejected by Dendrite servers.Patches
gomatrixserverlib contains a fix as of commit
723fd49and Dendrite 0.9.3 has been updated accordingly.Workarounds
Matrix rooms where the
"events_default"power level has not been changed from the default of zero are not vulnerable.For more information
If you have any questions or comments about this advisory, e-mail us at security@matrix.org.