Keycloak-services: keycloak-services: ciba sub parameter injection causes attacker authentication to issue victim tokens
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Not reported
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 26/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
The Keycloak identity service's CIBA authentication endpoint fails to validate the sub parameter, so an attacker who can log in with their own account can make the server issue security tokens belonging to a different user. Remote attackers with low-privilege credentials can exploit this over the network without any action from the victim, gaining unauthorized access to the victim's account.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
A flaw was found in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak. The CIBA endpoint fails to properly validate the sub parameter, allowing it to be stored as an additional request parameter. During the token issuance process, this injected value overwrites the legitimate subject identifier. This allows an attacker to authenticate as themselves but receive security tokens belonging to a different victim user, leading to unauthorized account access.
cve.now Index
- Exploitation0/40No signal
- Exposure3/25Reachable over the network · Unknown: No advisory context yet
- Reach10/20Shipped in major Linux distributions
- Severity7.8/10CVSS 6.8, total technical impact per CISA
- No patch5/5No patch listed yet
What would change the score
- Would score about 81 if added to CISA KEV
- Would score about 76 if CISA's SSVC rates exploitation active
- Would score about 45 if advisories confirm default setups are exposed
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- keycloak-services
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- keycloak-services
Version range not reported
Evidence 2
- Report
- Link
Corrections
None so far.
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