Ash.Reactor change step fails open, skipping a change when its where guard raises
8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 2.1epss 0.1%
exploitation probability
0.1%top 97% of all CVEs
observed exploitation
nono source reports it
Not Failing Securely (Failing Open) vulnerability in ash-project ash skips an Ash.Reactor change when the guard controlling it raises, so a change meant to run does not.
An Ash.Reactor change step can be gated by where validations that decide whether the change runs. Ash.Reactor.ChangeStep (lib/ash/reactor/steps/change_step.ex) evaluated those guards in apply_where_clauses/3, and apply_validation rescued any exception into {:error, error}. The reduce treated that identically to a guard whose condition was simply not met and bypassed the change. So when a guard raises (for example on attacker-influenced input), a change that enforces a security-relevant modification is skipped rather than failing the step. The fix distinguishes a raised exception (now {:raised, error}) and halts the step with an error, failing closed.
This issue affects ash: from 3.0.0-rc.17 before 3.32.2.
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
ash-project · ash