cbcvebase.
CVE-2010-4052
published 2011-01-13

CVE-2010-4052: Stack consumption vulnerability in the regcomp implementation in the GNU C Library (aka glibc or libc6) through 2.11.3, and 2.12.x through 2.12.2, allows…

PriorityP344medium5CVSS 2.0
AVNACLAuNCNINAP
EXPLOIT
EPSS
51.30%
98.8th percentile
Stack consumption vulnerability in the regcomp implementation in the GNU C Library (aka glibc or libc6) through 2.11.3, and 2.12.x through 2.12.2, allows context-dependent attackers to cause a denial of service (resource exhaustion) via a regular expression containing adjacent repetition operators, as demonstrated by a {10,}{10,}{10,}{10,} sequence in the proftpd.gnu.c exploit for ProFTPD.

Affected

33 ranges· showing 25
VendorProductVersion rangeFixed in
debianglibc< glibc 2.19-4 (bookworm)glibc 2.19-4 (bookworm)
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc
gnuglibc

Detection & IOCsextracted from sources · hover to see the quote

urlhttp://cxib.net/stuff/proftpd.gnu.c
command.*{10,}{10,}{10,}{10,}
commandHideFiles "(\.ftpaccess|(.*{10,}{10,}{10,}{10,}))$"
commandHideFiles "(\.ftpaccess|(.*{10,}{10,}{10,}{10,}{10,}))$"
commandHideFiles "(.*+++++++++++++++++++++++++++++(\w+))"
filename.ftpaccess
commandstat {a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}{a,b}
  • Detect FTP STAT commands containing repeated brace-expansion wildcard patterns (e.g., {a,b} repeated 48+ times) sent by anonymous users, which trigger CPU exhaustion in ftpd via glob(3).
  • Monitor for creation of a .ftpaccess file via FTP STOR containing HideFiles directives with nested quantifier regex patterns such as {10,}{10,}{10,}{10,} or adjacent '+' operators, which exploit regcomp() in glibc.
  • Alert on proftpd child processes consuming 100% CPU for extended periods (600+ minutes), which is a runtime indicator of successful CVE-2010-4052 exploitation.
  • Detect regcomp() calls with regex patterns containing adjacent repetition operators (e.g., {10,}{10,}{10,}{10,}) passed from untrusted input, particularly in network-facing daemons like proftpd or ftpd.
  • ·Red Hat assessed CVE-2010-4052 as not a security issue for RHEL 4/5/6, stating that applications using regcomp()/regexec() on untrusted input without sanity-checking are responsible for the limitation; no fix was planned.
  • ·The exploit requires write privileges to the FTP server to upload a malicious .ftpaccess file containing the HideFiles regex payload; without write access, only the direct STAT wildcard vector applies.
  • ·The amount of stack memory available to the glibc regex engine determines the size of input required to trigger the crash; environments with larger stack limits require longer/more complex patterns.

CVSS provenance

nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P
osv5.0MEDIUM
vendor_debian5.0LOW
vendor_redhat5.0MEDIUM
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