Security readout for executives and security teams
Plain-English summary
CVE-2023-42793 lets an unauthenticated attacker bypass TeamCity Server login and gain remote code execution on vulnerable servers. Because TeamCity often controls build pipelines and secrets, compromise can affect software delivery, credentials, and downstream systems.
Executive priority
Immediate remediation is warranted for any vulnerable TeamCity Server. This is a critical, known-exploited CI/CD compromise path that can affect software integrity and operational continuity, not just the TeamCity application itself.
Technical view
JetBrains TeamCity before 2023.05.4 contains a CWE-288 authentication bypass enabling network-based, low-complexity RCE without credentials or user interaction. The CVSS 3.1 score is 9.8 with high confidentiality, integrity, and availability impact.
Likely exposure
Organizations running self-managed JetBrains TeamCity Server versions before 2023.05.4 are exposed, especially if the server is internet-accessible or reachable from untrusted networks. Build agents, CI/CD secrets, signing material, and deployment credentials may be at risk after server compromise.
Exploitation context
Active exploitation is supported by CISA KEV, and cited public reporting says patched TeamCity servers were being targeted. Public exploit-oriented references are listed in the source bundle, so unpatched reachable instances should be treated as high-priority incident candidates.
Researcher notes
The source bundle supports the core chain as authentication bypass to RCE in TeamCity Server before 2023.05.4. Avoid assuming specific intrusion methods beyond cited sources. Focus validation on version exposure, reachability, server integrity, and downstream CI/CD credential impact.
Mitigation direction
- Upgrade TeamCity Server to 2023.05.4 or a later fixed version.
- Restrict TeamCity access to trusted networks and authenticated administrative paths.
- Review JetBrains guidance for any additional vendor-specific remediation.
- Rotate CI/CD secrets, tokens, and deployment credentials if compromise is suspected.
- Investigate exposed vulnerable servers before returning them to normal operation.
Validation and detection
- Inventory all TeamCity Server instances and record exact versions.
- Confirm no self-managed server remains below version 2023.05.4.
- Check whether any TeamCity Server was internet-accessible during the exposure window.
- Review TeamCity, proxy, and identity logs for suspicious unauthenticated administrative activity.
- Validate build pipeline secrets and deployment credentials have not been misused.
Public sources used
Michael Williams reviewed this cited source version on .
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-288: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2023-42793 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.jetbrains.com/privacy-security/issues-fixed/CVE reference
- https://blog.jetbrains.com/teamcity/2023/09/cve-2023-42793-vulnerability-post-mortem/CVE reference
- https://attackerkb.com/topics/1XEEEkGHzt/cve-2023-42793CVE reference
- https://www.securityweek.com/recently-patched-teamcity-vulnerability-exploited-to-hack-servers/CVE reference
- https://www.rapid7.com/blog/post/2023/09/25/etr-cve-2023-42793-critical-authentication-bypass-in-jetbrains-teamcity-ci-cd-servers/CVE reference
- https://www.sonarsource.com/blog/teamcity-vulnerability/CVE reference
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-42793CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Authentication Bypass Using an Alternate Path or Channel
Authentication Bypass Using an Alternate Path or Channel represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.