GitHub Enterprise Server: Deserialization of Untrusted Data
CVE-2022-23734 is a high-severity deserialization of untrusted data vulnerability in GitHub Enterprise Server from GitHub, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 3.2.16, 3.3.11, 3.4.6 as the first without the flaw, so updating GitHub Enterprise Server to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.76% chance of exploitation within 30 days, higher than 86% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update GitHub Enterprise Server to 3.2.16 or 3.3.11 or 3.4.6 or 3.5.3, whichever matches your release line, or a later version.
- Update Enterprise Server to 3.2.16 or 3.3.11 or 3.4.6 or 3.5.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| GitHub | GitHub Enterprise Server | 3.2 up to, but not including, 3.2.16; 3.3 up to, but not including, 3.3.11; 3.4 up to, but not including, 3.4.6; 3.5 up to, but not including, 3.5.3 | 3.2.16, 3.3.11, 3.4.6, 3.5.3 |
| GitHub | Enterprise Server | before 3.2.16; 3.3.0 up to, but not including, 3.3.11; 3.4.0 up to, but not including, 3.4.6; 3.5.0 up to, but not including, 3.5.3 | 3.2.16, 3.3.11, 3.4.6, 3.5.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.1 | 8.8 | High | CISA (ADP) |
Official description
A deserialization of untrusted data vulnerability was identified in GitHub Enterprise Server that could potentially lead to remote code execution on the SVNBridge. To exploit this vulnerability, an attacker would need to gain access via a server-side request forgery (SSRF) that would let an attacker control the data being deserialized. This vulnerability affected all versions of GitHub Enterprise Server prior to v3.6 and was fixed in versions 3.5.3, 3.4.6, 3.3.11, and 3.2.16. This vulnerability was reported via the GitHub Bug Bounty program.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in GitHub Enterprise Server
- 7.6 High severity
- 9.8 Critical severity
- 7.2 High severity
- 7.2 High severity
- 9.8 Critical severity
- 7.2 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.1 Critical severity
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