7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7 High
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
15.7%
An attacker can exploit a critical flaw in the application to initiate a Denial of Service (DoS) attack, rendering the application inoperable and affecting all users. The issue arises from unsafe manipulation of an array in a multi-threaded environment.
The vulnerability is rooted in the application’s code, where an array is being modified while it is being iterated over. This is a classic programming error but becomes critically unsafe when executed in a multi-threaded environment. When two threads interact with the same array simultaneously, the application crashes.
The core issue is located in expireOldFailedAttempts function:
func expireOldFailedAttempts(maxAge time.Duration, failures *map[string]LoginAttempts) int {
expiredCount := 0
for key, attempt := range *failures {
if time.Since(attempt.LastFailed) > maxAge*time.Second { expiredCount += 1
delete(*failures, key) // Vulnerable code
} }
return expiredCount }
The function modifies the array while iterating it which means the code will cause an error and crash the application pod, inspecting the logs just before the crash we can confirm:
goroutine 2032 [running]: github.com/argoproj/argo-cd/v2/util/session.expireOldFailedAttempts(0x12c, 0xc000adecd8)
/go/src/github.com/argoproj/argo-cd/util/session/sessionmanager.go:304 +0x7c github.com/argoproj/argo-cd/v2/util/session.(*SessionManager).updateFailureCount(0xc00035 af50, {0xc001b1f578, 0x11}, 0x1)
/go/src/github.com/argoproj/argo-cd/util/session/sessionmanager.go:320 +0x7f github.com/argoproj/argo-cd/v2/util/session.(*SessionManager).VerifyUsernamePassword(0xc 00035af50, {0xc001b1f578, 0x11}, {0xc000455148, 0x8})
To reproduce the vulnerability, you can use the following steps:
expireOldFailedAttempts()
function being called in multiple threads.This is a Denial of Service (DoS) vulnerability. Any attacker can crash the application continuously, making it impossible for legitimate users to access the service. The issue is exacerbated because it does not require authentication, widening the pool of potential attackers.
github.com/argoproj/argo-cd
github.com/argoproj/argo-cd/blob/54601c8fd30b86a4c4b7eb449956264372c8bde0/util/session/sessionmanager.go#L302-L311
github.com/argoproj/argo-cd/commit/2a22e19e06aaf6a1e734443043310a66c234e345
github.com/argoproj/argo-cd/commit/5bbb51ab423f273dda74ab956469843d2db2e208
github.com/argoproj/argo-cd/commit/ce04dc5c6f6e92033221ec6d96b74403b065ca8b
github.com/argoproj/argo-cd/security/advisories/GHSA-6v85-wr92-q4p7
nvd.nist.gov/vuln/detail/CVE-2024-21661
7.5 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7 High
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
15.7%